Determination Of Molar Mass Lab Report


) A convenient method of determining the volume of a container of irregular shape is to fill it with a liquid of known density and measure the mass. This value, along with the known mass of benzoic acid, leads to the molar mass determination. 551×10-3mol From the reaction, NaOH and KHP reacted in a 1:1 mole ratio. What is the molar mass of the gas? 2. mH 2 O in the hydrate equals m Ca(NO 3) 2 4H 2 O-m Ca(NO 3) 2. Now you need to find the moles to complete the problem. Add approximately 2 g of the unknown to the naphthalene using the wide stem funnel. You need this equipment: 600-mL beaker, thermometer, large test tube, 250-mL wide-mouth glass bottle, paper towels, wire gauze, clamp, standard laboratory balance, analytical balance, Bunsen burner, rubber hose, wire stirrer, weighing paper. The group will utilize prior knowledge concerning gas laws, lab skills and equipment. the molar mass of a solute by measuring the freezing point depression of t-Butanol when that solute is added to it. Please convert the following variables to the correct units in order to use the gas law constant R (0. Answer the following questions on a separate piece of paper : Suppose you have a stoppered flask containing CO2 gas at room temperature and pressure. Calculate the percentage of sugar in the gum by dividing the mass of the dissolved sugar by the mass of the unchewed gum and multiply by 100. Lab 7 - Determination of the Molar Mass of an Unknown Solid by. if Trial # 1 gives a mass of 240 g/mol and Trial # 2 gives 256 g/mol the average should be reported as 248 8 g. 200 g of benzoic acid and record the mass. Report the uncertainty as half of the difference between the two mass measurements (ex. Determine molar mass, size, and relative fractions. The vol-ume in the buret is read, to the nearest 0. 1M aqueous solution of NaCl Get the answers you need, now!. Step 8: Remove the foil from the flask and clean out. 50 mL of H 2. Record the answer in your data table. Reference ranges for blood tests are studied within the field of clinical chemistry (also known as "clinical biochemistry", "chemical pathology" or "pure blood chemistry"), the area of pathology that is generally concerned with analysis of bodily fluids. What is the molar enthalpy of combustion of magnesium?. Report Determine the mass of the vapor in the flask for each trial Determine the mass of water in the flask and use the density to calculate the volume of water in the flask. The molecular weight of air was found to be 26. Determine the mass of the final dried calcium carbonate product. MOLAR MASS OF A GAS Group Members: _____ _____ _____ _____ As a group, design an experiment to measure the molar mass of the gas in the lighter. 3og-10, lag = 74. 002 L gas let out) 5. Chemistry 321: Quantitative Analysis Lab Webnote Gravimetric Analysis: Determination of % Sulfur in Fertilizer This is another "real world" sample experiment – in this case we will analyze a fertilizer sample for the sulfate content and express the result as %S. Calculate the amount (in moles) of Mg and MgO reacted, using the known molar masses and your measured mass values. 150 mL beaker. 00352 moles). IB Chemistry HL Name: Yoojin Lee Candidate Number: 002213-067. The purpose of this experiment is to determine the molar volume of hydrogen gas by. The pKa was found to be 3. Experiment Overview. 5 grams of the sample into the test tube and weigh. I am trying to find the molarity of the acid but I don't know the molar mass of the unknown acid to finish my problem. 8 o C and has a freezing point depression constant, \(K_{f}\) = 40 o C/molal. Molar Mass Determination by Depression of the Freezing Point February 7, 2012 Adrienne Oxley Lab Partner: Everett Spell Title page includes the name of the experiment, the date, your name and your lab partner's name. 175 g; Temperature of water in flask: 22. AP6356 Publication No. Sketch a simple diagram of the graph into your lab report. 01 mL, at the bottom of the meniscus (the concave surface of the aque-ous solution). Ascorbic Acid Titration of Vitamin C Tablets This lab will be completed individually! Make sure you come prepared! Introduction Vitamin C (also known as ascorbic acid, HC 6 H 7 O 6) is a necessary ingredient in the human diet. Determine the viscosity average molecular weight of a polymer. Viscosity is an internal property of a fluid that offers resistance to flow. To measure an accurately the gas has to be a STP (Standard Temperature and Pressure). 22 g/mol No. freezing point depression in part 2 and the freezing point depression constant for the t-butyl alcohol. Lab Session 11, Experiment 10: Determination of the Molar Mass of Oxygen. pdf] - Read File Online - Report Abuse. The atomic mass (or weight) of Na is 22. The density of water at 25oC is 0. 81 g/mole= molar mass of butane gas. To start the experiment, a beaker was filled with water and then a cage was created with a copper wire. Find the data table included with this lab and familiarize yourself with its layout. Part B: Determining the molar mass of an unknown diprotic acid (H 2 A). The molar mass of the butane gas was calculated by dividing the mass of butane gas in grams(0. Repeat the calculation above for solution 2 remembering to use the total mass of solute, line 6 of the data table, and the ΔTf for solution 2. Molar Volume of a Gas – 10/27/08 Alic Albright, Josh Coleman, Dan Boden, Zach Babin Purpose: The pupose of this lab was to make an experimental determination of a molar volume through reaction of the substance shown: Mg(s) + 2HCl(aq) > MgCl(aq) + H(g) Introduction: In this lab, a magnesium ribbon and HCl are combined in a gas measuring tube. You need this equipment: 600-mL beaker, thermometer, large test tube, 250-mL wide-mouth glass bottle, paper towels, wire gauze, clamp, standard laboratory balance, analytical balance, Bunsen burner, rubber hose, wire stirrer, weighing paper. Determine the pressure of the hydrogen gas at the conditions of this experiment. The composition of the product can be estimated by assuming a linear relation between refractive index and molar concentration. Chemical and physical methods for determining atomic and molecular formula weights or molar masses have been important historically as a way of analyzing and categorizing new materials. At the end of the lab is an example page of how to do the calculations on page 22 after you have completed the data. To become familiar with colligative properties; To be able to use these properties to determine the molar mass of a substance. The objective of this part is to test your ability to perform a routine lab analysis and use a pipet. To determine the molar mass of a gas based on a knowledge of its mass, temperature, pressure, and volume. 453 grams/mole. Freezing Point Depression Report. txt) or read online for free. 25 x 10-4 moles) Volume of H2 gas produced 8. A deficiency of Vitamin C leads to the disease scurvy, at one time commonly occurring during long sea voyages. Colligative Properties: Freezing Point Depression and Molar Mass Experiment 17 17-3 23. Answer the following questions on a separate piece of paper : Suppose you have a stoppered flask containing CO2 gas at room temperature and pressure. The mass, pressure, volume and tem-. 0158 g/mol (molar mass of H2) and 22. 44g of NaCl in a final volume of 1 liter, you have made a 1M NaCl solution, a 1 molar solution. The Balanced equation is what follows: M2CO3 + 2HCl ­­­> CO2 + 2MCl + H2O. A 20x stock would be prepared at a concentration of 20*0. A simple calculation using the periodic table would provide the correct answer for the molar mass of carbon dioxide, however, one can also conduct an experiment and try to reach the accepted value. 6 g/mole The molar mass of the gas mixture was found to be 66. Concepts • Dalton's law • Ideal gas law • Molar mass Materials Balance, centigram precision (0. Add approximately 2 g of the unknown to the naphthalene using the wide stem funnel. Lab Lectures Online Chem 142 1 of 4 Lab 5: Gas Laws Determining the Molar Mass of a Low-Boiling Liquid Introduction In this experiment, you will determine the molar mass and identity of a liquid that boils at a low temperature. Select File/PrintGraph and print 2 copies of this plot to be attached to your lab reports. Molar Mass by Freezing Point Depression Lab Video Explanation nathanjones0117. Show how you determined the freezing point from the graph (one of the two trials): 3. Property Given Values Converted to correct units Pressure 725 mm Hg Volume 1,234 mL mass 17. In this experiment, the molar mass of oxygen will be determined. Lab: Determining the Molar Mass of Butane Introduction In many laboratory settings, a gas must be collected for study. In an electrolysis cell similar to the one employed in this experiment, a student observed that his unknown metal anode lost 0. Fill the flask with water and then pour the water from the flask into a 500 mL graduated cylinder. 42 g/mol Oleic acid 282. Be careful not to lose any sample of lauric acid that may have solidified to the thermometer or swizzle. 000 g)(100) = 36. Here the read-ing would be approximately 9. Determination of Empirical Formulas In this lab you will synthesize zinc iodide from zinc metal and solid iodine. The determination of the molar mass of the unknown acid by titration would not have been. Titration Of An Unknown Acid Lab Report. 04 molar per second. Using the freezing points of the pure phenyl salicylate and the experimentally synthesized benzoic acid/phenyl salicylate solution (Solution #3) along with the determined molal freezing point depression constant of phenyl salicylate, Kp and van't Hoff factor, i, determine the molar mass of the experimentally. The method was designed by a French chemist named Jean Baptiste André Dumas, after whom the procedure is now named. 4 mol / kg, and the molality of Solution 2 is 4. Add the mass of HCl and the mass of NaOH to give the total mass used, this will be the mass you will use to calculate heat of reaction, q. 740 g a) Find the molar mass of this arsenic chloride. Objective: The objective of this experiment is to determine the molar mass of an unknown solute by measuring the freezing point depression of a solution of this solute in a solvent as compared to the freezing point of the pure solvent. 05*g*mol^-1 And how did we get this quantity? All I did was take the molar mass of each element in the formula of acetic acid, weighted according to its frequency, i. DATA Data for Unknowns: Unknown # 3 Mass of Trial 1, mass/g Trial 2, mass/g First weighing Paper and solid 3. 00010 g (or 0. Based on the the molar mass of the gas produced in this lab, a possible formula for the gas could be C4H9. 5580 g solute = 153 g/mole 0. Next determine the moles of carbon dioxide produced (Hint: molar mass of carbon dioxide), the moles of unknown sample (Hint: balanced equation), and then the molar mass of the unknown sample in grams/mole. to the mass collected for the flask containing residual contents and empty cup. Attach the temperature – time graphs as directed in the lab manual (both trials may be plotted on the same graph). State a hypothesis, the problem, procedures, SAFETY, materials and equipment. Introduction: The molar masses of compounds are used daily in the chemistry profession. You can now use what you know about the relationship between atomic weight and molar mass to calculate the mass of 1 mole of H 2O, water. Molar Volume of a Gas - 10/27/08 Alic Albright, Josh Coleman, Dan Boden, Zach Babin Purpose: The pupose of this lab was to make an experimental determination of a molar volume through reaction of the substance shown: Mg(s) + 2HCl(aq) > MgCl(aq) + H(g) Introduction: In this lab, a magnesium ribbon and HCl are combined in a gas measuring tube. 42 g/mol Oleic acid 282. Determine the Kelvin temperature of the gas in the tube. Mass of test tube and foil cover (g) 10. molar mass= grams /moles , so we need to find the grams and divide that # by the number of moles. 16 g, a pKa of 7. 69 Temperature of water bath (degrees C) 100. Titration Of An Unknown Acid Lab Report. The variable n can be written as Substitute this quotient for n in the ideal gas equation and solve for the molar mass. (Brady & Senese 2004, 118-120). of any pure substance has a mass in grams exactly equal to that substance’s atomic or molecular mass (mass of one mole of a substance). LAB – Using Hess’ Law and calorimetery to determine the molar enthalpy of combustion of magnesium. Determine the combined total mass of a dry 125 mL Erlenmeyer flask, a rubber band, and a square of aluminum foil, and record this mass on the report form. This lab could have been improved by adding ice in between each addition of solution 1 so each. mL at 27°C and 650. Determine size and number density with just a light scattering. molar absorptivity could be used to determine the concentration of unknown #285. The weight of the glass bottle, of the lighter, and of the bottle cap was measured. Chemical and physical methods for determining atomic and molecular formula weights or molar masses have been important historically as a way of analyzing and categorizing new materials. Sketch a simple diagram of the graph into your lab report. 98 g/mol but 124. where n solute is measured in moles and the mass solvent is measured in kilograms. The freezing point depression can be determined by subtracting the temperature of the solution by the temperature of the water. 0021 moles 2. Using the experimental ∆Tf value and the reported Kf value in equation (1) will enable you to find the amount (in moles) of benzoic acid in your solution. pdf), Text File (. 9994 g/mol and the molar mass of hydrogen is 1. After determining the volume of NaOH required to titrate the acetic acid solution, further calculations and observations revealed the molarity of unknown acetic acid ID #138 to be about 1. You would rearrange. The freezing point apparatus consists of a freezing point test tube fitted with a stopper, a digital thermometer and a stirring wire. 5) there is in plant food. Then divide the grams of solute by the moles to determine the molar mass. The atomic weight of chlorine is 35. 02 (minor additions and corrections), May 2000. 160 M) and the molarity of. Do Not Allow The Magnetic Stir Bar To Fall Into This Container!! 24. The molality of Solution 1 is 2. Prepare a gas chromatography/mass spectrum (GC/MS) sample of your product using the following method: Put 2-3 drops of your product into a small test tube. Then, you would determine the mass of Tris-HCl you need. One mole of H 2 SO 4 is therefore two equivalents, and one equivalent is ½ mole of H 2 SO 4. Determination of the Molar Mass of Ethanol Abstract: The molar mass of ethanol was determined by using the ideal gas law. The two tablets analyzed were only 1% different in mass, but had an average of 8% difference in the mass of acetylsalicylic acid present. *Note– this pre-lab must be finished before you come to lab. Lab Session 11, Experiment 10: Determination of the Molar Mass of Oxygen. By subtracting the weight of the empty test tube, you obtain the weight of sample, which should not be more than 1. Its equivalent weight would be the mass of ½ mole of. Molar Mass of a Vapor OBJECTIVES To observe how changes in pressure, for a fixed amount of a trapped gas at constant temperature, can affect the volume of the gas. Molar Mass of a Volatile Liquid Lab Report - Free download as Word Doc (. The molar mass is an important value that must be known in order to identify an unknown substance or to characterize a. The calculated molar mass was found to be 67. replace n (moles of gas) with g/MM where g is the mass of the gas and MM is the molar mass of the gas. 150 mL beaker. This is used to find the unknown substances by doing precipitation reactions. c) Find molar mass of solute: Molar mass of solute = 0. Determine the viscosity average molecular weight of a polymer. 01 g of liquid camphor, the freezing point of the mixture is found to be 176. You can then get a mass ratio, which you can convert into a mole ratio. The molar mass of unknown gas was found to be 47±6g. Q: How much are we allowed to collaborate on this lab report?. Terms to Know Molar Mass - The number of grams per mole of a substance. Lab Lectures Online Chem 142 1 of 4 Lab 5: Gas Laws Determining the Molar Mass of a Low-Boiling Liquid Introduction In this experiment, you will determine the molar mass and identity of a liquid that boils at a low temperature. Therefore, by determining the mass of magnesium that reacts and the number of moles that this mass is equal to, you will also determine the number of moles of hydrogen gas produced. Enthalpy Lab Enthalpy Lab. Name AB A LOCAL Partner's Name MA R ENDALL Total mass of product synthesized in previous experiment (6) 1720 g Molarity of KMnO. Goals To determine the molar mass of a condensable vapor through use of the ideal gas law. 2) Convert average volume from step 1 from ml to liters. 25 x 10-4 moles) Volume of H2 gas produced 8. View Lab Report - Chem Lab Report 4. (Record from the label on the container) Trial 1 Trial 2 Trial 2 0. 90 / , = ; = = and is the mass of the solute and solvent, respectively. Download this page: =>MolecularWeight. 4T: Tutorial Assignment 3. "Molar mass" = {2xx12. The goal of the lab was to determine the molar mass and the plausible formula of the chemical, using a glass bottle, a lighter, and a handful of laboratory equipments. Experiment*1,*Hydrates* 124* ( Positionthecrucibleinsideawiretrianglesupportedbya tripod( (see( Figure( 1M1). replace n (moles of gas) with g/MM where g is the mass of the gas and MM is the molar mass of the gas. The Dumas method is used to determine the density of each vapor; and then the molar mass is calculated. The purpose of the diffusion lab was to demonstrate how diffusion works across cell membrane with dialysis tubing. The real cell system in the second lab was a potato. EXPERIMENT 12B: TITRATION OF AN UNKNOWN ACID INTRODUCTION In this experiment you will determine the molar mass of an unknown acid by titration with the sodium hydroxide you prepared and standardized in experiment 12A. We will use carbon-12 as an example because it is the standard for the formal definition of the mole. The purpose of the experiment was to use the concept of freezing point depression to determine the molar mass of a compound by determination of the freezing point of a pure solvent and a solution. 0987 g Volume used (first equivalence point) = 10. pdf Put your unknown in the oven at 150 °C for at least 30 minutes, while you prepare your EDTA solution and do your standardization titrations. You will also need about 20 mL of 0. This lab handout! Questions (show all work): 1. to the mass collected for the flask containing residual contents and empty cup. 50 mL Molar mass of KHP = 204. 01 g of liquid camphor, the freezing point of the mixture is found to be 176. Molar Mass of a Vapor OBJECTIVES To observe how changes in pressure, for a fixed amount of a trapped gas at constant temperature, can affect the volume of the gas. Next determine the moles of carbon dioxide produced (Hint: molar mass of carbon dioxide), the moles of unknown sample (Hint: balanced equation), and then the molar mass of the unknown sample in grams/mole. 041 g/mol 2) The mass of water in one mole of the hydrate is: 322. (see calculations section for details on each step) Procedure, Part II - Determination of the Mass of a Piece of Magnesium. 43 L (molar volume of an ideal gas) were used to calculate the density of hydrogen gas. For example, to make a five liter solution of 50 millimolar NaCl and ten millimolar tris-HCl, you would first determine the mass of NaCl that you need. Using the Kf you determined in part 2 you can now determine the molar mass of the unknown. According to the definition, one mole of carbon-12 has a mass of exactly 12 grams. Determining the Molar Mass of the Unknown (write the unknown # _____) Mass of t-butyl alcohol: _____ g. -cm strip of the same type of ribbon. The Ka and Molar Mass of a Monoprotic Weak Acid Chemistry Lab 152 Professor: James Giles November 7, 2012 Abstract: The purpose of this experiment was to determine the pKa, Ka, and molar mass of an unknown acid (#14). 420 g mass of vessel filled with water at 23°C = 638. Read Lab 10. the Molar Mass of a Volatile Liquid by the Dumas Method Evan Contreras Texas A&M University Corpus Christi General Chemistry II Laboratory Mr. Determining Molarity Through Acid-Base Titration. 539 Moles of Solute = molality x masso solvent 0. Using the freezing points of the pure phenyl salicylate and the experimentally synthesized benzoic acid/phenyl salicylate solution (Solution #3) along with the determined molal freezing point depression constant of phenyl salicylate, Kp and van't Hoff factor, i, determine the molar mass of the experimentally. 4 molecular concentration because potatoes are more moist than. http://www. 3og-10, lag = 74. We found our percent yield to be 105%, and this was calculated by dividing our lab’s molar volume by the theoretical molar volume. Calculate the amount (in moles) of Mg and MgO reacted, using the known molar masses and your measured mass values. Freezing-Point Depression and Molar Mass. pdf] - Read File Online - Report Abuse. A simple calculation using the periodic table would provide the correct answer for the molar mass of carbon dioxide, however, one can also conduct an experiment and try to reach the accepted value. The density of water at 25oC is 0. *Note– this pre-lab must be finished before you come to lab. If the substance in question is a volatile liquid, a common method to determine its molar mass is to vaporize it and apply the ideal gas law, PV = nRT to the data collected. asked by jared on May 16, 2007; 12 Chemistry. Print out this page also. Molar mass of citric acid (C₆H₈O₇):. The Objective of this lab is to experimentally determine the molar mass of an unknown and volatile liquid. In an acid such as H 2 SO 4, one mole can produce two moles of H +. 02 g/mol (rounded molar mass of H2) and 22. The pKa was found to be 3. DISCUSSION. One mole of H 2 SO 4 is therefore two equivalents, and one equivalent is ½ mole of H 2 SO 4. The freezing point depression of Solution 1 is -4. Clamp the neck of the flask to maintain the flask in the boiling water. And we observe the initial rate of our reaction to be. To become familiar with colligative properties; To be able to use these properties to determine the molar mass of a substance. 184 J/g·°C). Let's become familiar with colligative properties and to use them to determine the molar mass of a substance. PURPOSE Prepare a titration curve for an unknown monoprotic weak acid, and from the titration curve determine the pK a and the molar mass. So how is molar mass determined and how is the molar mass of an unknown found? In this experiment, the molar mass of butane, C 4H 10, will be calculated based on physical measurements of mass, volume, temperature and pressure. Purpose: Experimental determination of standard molar volume. Experiment*#4. Answer the following questions on a separate piece of paper : Suppose you have a stoppered flask containing CO2 gas at room temperature and pressure. 0158 g/mol (molar mass of H2) and 22. mL at 27°C and 650. ) Calculate the true volume of the flask. Due to the Law of Conservation of Mass, one would predict that after any number of chemical reactions and phase changes, the final mass and number of moles of copper would remain the same as the initial amounts. 00352moles= 56. IB Chemistry HL Name: Yoojin Lee Candidate Number: 002213-067. Using the freezing points of the pure phenyl salicylate and the experimentally synthesized benzoic acid/phenyl salicylate solution (Solution #3) along with the determined molal freezing point depression constant of phenyl salicylate, Kp and van't Hoff factor, i, determine the molar mass of the experimentally. The box was filled with water. xxxx g of your solid unknown. All you need to do is multiply the number of each type of atom by its atomic mass (which you can find on the back cover of the lab manual), and then add up the total masses for each element. 50 g of the unknown acid in 25 mL of water in an Erlenmeyer flask, add 2 drops of phenolphthalein and titrate with the 0. Determining the Molar Mass of an Unknown Carbonate Using the Ideal Gas Law In this lab you will determine the molar mass of an unknown carbonate by using the ideal gas law to determine the number of moles of carbon dioxide produced when the carbonate reacts with hydrochloric acid. Celsius (0°C) or 273 Kelvin (273K). 1353 mol malar mass of unknown: tla0 x 1000 g 1000910 1Z9135. First, assume that the volume of the vessel in mL is the same as the mass of the water that fills the vessel. State a hypothesis, the problem, procedures, SAFETY, materials and equipment. 01 g of liquid camphor, the freezing point of the mixture is found to be 176. Experiment*#4. Clamp the neck of the flask to maintain the flask in the boiling water. solute, in Eq 6 to determine the molar mass, M, of your unknown compound. m = molality of the solution = (moles of solute)/(mass of solvent in kg) K f = molal freezing point depression constant (this constant is solvent dependent) K f (naphthalene) = 6. Mass of empty calorimeter cup (Mc) _____ g 2. Sucrose is considered a green compound for this lab because it requires no hazardous material disposal and produces no toxic fumes. Its equivalent weight would be the mass of ½ mole of. pdf Determination of Molecular Weight. Determining the Molar Volume of a Gas Purpose: The purpose of this lab is to determine the molar volume of H 2 at room temperature and standard pressure. We know this by looking at the periodic table. Collect H2 over H2O and measure volume (gas collecting tube) at room temperature. NOTE: You can submit your answers up to three times. Determining Molarity Through Acid-Base Titration. mm Hg and 28°C. 44 g/mole mmoles of AgNO 3 = × = 4. The balanced equation for this reaction shows that the molar ratio of magnesium reacted to hydrogen gas produced is 1:1. The sodium hypochlorite mass percent is found from the mass of sodium hypochlorite in 25. distilled water 15 mL beaker. The method you will use was developed by JBA Dumas (1800-1884), a French. Introduction: This experiment focused on colligative properties. 551×10-3mol From the reaction, NaOH and KHP reacted in a 1:1 mole ratio. Would the calculated atomic mass be larger or smaller than the true value if water vapor pressure is ignored? 3. Stockroom You will need a hot plate. Mass of water in flask: g Density of water: gcm-3 at ºC Volume of flask: mL L Trial 1 Trial 2 Trial 3 Trial 4 Mass of flask with foil and vapor (g) Mass of flask with foil w/out vapor (g) Mass of vapor (g) Temperature (ºC) Temperature (K) Molar Mass (MM). 0158 g/mol (molar mass of H2) and 22. Freezing-Point Depression and Molar Mass. Mg+_____HCl →MgCl_____+ _____H 2(g) 2. Diffusion Osmosis Lab Report. 00845 L) Temperature 23 oC 23 oC 23 oC Barometric pressure 735 mmHg 735 mmHg 735 mmHg Partial pressure of H2O 21. Done by: Seonlim Lee (Lynn) G. Colligative Properties: Freezing Point Depression and Molar Mass Experiment 17 17-3 23. 94 g P + 128. Pre-Laboratory Assignment: Determination of Molar Mass by Freezing Point Depression Camphor melts at 179. txt) or read online for free. To measure an accurately the gas has to be a STP (Standard Temperature and Pressure). This is one of the longer lab reports this semester, so begin work on it early. 10% The theoretical (actual) percent hydration (percent water) can be calculated from the formula of the hydrate by dividing the mass of water in one mole of the hydrate by the molar mass of the hydrate and multiplying by 100. The box was filled with water. In an acid such as H 2 SO 4, one mole can produce two moles of H +. 160 M) and the molarity of. 1 mL Temperature: 21. NOTE: If you need to exchange your flask for any reason, be sure to re-weigh the new flask, as the weights of even the same sized flasks vary considerably. xxxx g of your solid unknown. 98 g/mol but 124. To determine the molar mass of a gas based on a knowledge of its mass, temperature, pressure, and volume. Collect H2 over H2O and measure volume (gas collecting tube) at room temperature. 0 g O = 357. [Filename: lab_3-_determination_of_molar_mass_by_vapor_density_840509. Determination of Molar Mass by Vapor Density 1. The real cell system in the second lab was a potato. By determining the loss in mass, one should be able to calculate the amount of sodium bicarbonate reacted and therefore the percent by mass of NaHCO 3 in the tablet. T-butyl Alcohol Lab Marquis Cuffee Chem 222 L 12/6/13 Abstract The goals of this experiment were to determine the freezing point of t-butyl alcohol, the molal freezing point constant for t-butyl alcohol, and the molar mass of an unknown substance. 81 g/mole= molar mass of butane gas. The atomic weight of chlorine is 35. 0158 g/mol (molar mass of H2) and 22. Molar Mass by Freezing Point Depression Lab Video Explanation nathanjones0117. Now you need to find the moles to complete the problem. Formal Lab Report: Molar Volume of a Gas at STP Abstract: The purpose of this experiment is to find out how to experimentally determine what the volume of a mole of H₂(g) is at STP by using gas laws. the chemical formula for aspirin is C9H8O4. Add about 15-20 g of naphthalene, mass accurately again, and record. The Molar Mass of a Gas Goals The purpose of this experiment is to determine the number of grams per mole of a gas by measuring the pressure, volume, temperature, and mass of a sample. The titration data are as following. Methodology Weigh a 200mm Pyrex test tube. Purpose: The purpose of this lab is to determine the molar volume of H 2 at room temperature and standard pressure. Using the mass of dried calcium carbonate, determine the number of moles of alkali metal carbonate present in the original sample. 4 molecular concentration because potatoes are more moist than. Lab for Finding Gas Constant R Title Purpose List equipment needed Step by step procedure Data table Calculations 1. Therefore, by determining the mass of magnesium that reacts and the number of moles that this mass is equal to, you will also determine the number of moles of hydrogen gas produced. - Mcw Data 1. Part of NCSSM CORE collection: This video shows the determination of the molar mass of a volatile liquid. Analysis: 1. The hydrogen gas produced will be collected by displacing water in a gas collection tube. What molecules are you using in this lab to determine the elemental masses of chlorine and bromine? 2. T-butyl Alcohol Lab Marquis Cuffee Chem 222 L 12/6/13 Abstract The goals of this experiment were to determine the freezing point of t-butyl alcohol, the molal freezing point constant for t-butyl alcohol, and the molar mass of an unknown substance. Determine its theoretical molar mass. Be careful not to lose any sample of lauric acid that may have solidified to the thermometer or swizzle. NOTE: You can submit your answers up to three times. 1 g/mol, calculate the value of n. Then, you would determine the mass of Tris-HCl you need. Solve for MM and write that gas law expression below: MM = b. The sodium hypochlorite mass percent is found from the mass of sodium hypochlorite in 25. 0 g/mol = 10 mol 4) Write the formula: Na2SO4 · 10H2O. Lab 7 - Determination of the Molar Mass of an Unknown Solid by Freezing Point Depression Goal and Overview In the first part of the lab, a series of solutions will be made in order to determine the freezing point depression constant, K f , for cyclohexane. Start with a clean, dry test tube and mass as before. 1M aqueous solution of NaCl Get the answers you need, now!. Calculate the molar mass for the gas for both trials and calculate the average value. 896 g was found to occupy a volume of 524 mL at 730. What is the molarity of a 6. For both parts A and B you will be taking several m. The molar mass is an important value that must be known in order to identify an unknown substance or to characterize a. Using the molality equation and the rest of the data collected during this lab, calculate the molar mass of benzoic acid from each trial and average the best trials. Describe the experimental data which would be needed to determine the molar. This can be done by producing H Molar Volume Determination Table Trial 1 Trial 2 Trial 3 Mass of magnesium piece (g) 0. determine the molar mass from this run. A solute need not to be a solid. You will also need about 20 mL of 0. In an electrolysis cell similar to the one employed in this experiment, a student observed that his unknown metal anode lost 0. the distance the light travels through the sample). Explain why changing an object's mass or volume does not affect its density (ie, understand density as an intensive property). 1353 mol malar mass of unknown: tla0 x 1000 g 1000910 1Z9135. edu Please attribute this work. AP Chemistry Lab 18 3 Determination of the Molar Mass and pK a of an Unknown Acid INTRODUCTION In this experiment you will determine the molar mass and K a of an unknown acid. Determine the change in boiling (or freezing) point temperature (solution and pure solvent). _____ Refer to your classroom discussion for help on questions 3 and 4. Collect H2 over H2O and measure volume (gas collecting tube) at room temperature. Remember there are. Conclusion: The purpose of this experiment was to determine the molar mass of an unknown, non-volatile solute. What we did in a nutshell: Very simple lab, we bubbled butane into a graduated cylinder and measure the displaced water as volume of gas. Molar Mass • The mass of one mole of atoms of any element is the molar mass which is numerically equal to the atomic mass unit (amu), but in grams… • Molar mass = __g = 1 amu 1 mole • Therefore CO 2 has an amu = 44. 0021 moles 2. You will use PERCENT ERROR for analysis. mm Hg and 28°C. 7) Using the answer to step 6 and the volume of the vinegar sample, calculate the mass of acetic acid per ml of vinegar. Conclusion: In this investigation, the molar mass of both butane and carbon dioxide was determined in order to gain insight into the effectiveness of the methodology, the behaviour of gases and explore the subject in greater depth. • To determine the molar mass of a volatile liquid. The sodium hypochlorite mass percent is found from the mass of sodium hypochlorite in 25. Any pure substance has a specific density at a specific temperature. The formula for this is Equation 2 in the section "Equations", a rearranged form of the original molality equation (Equation 1). 25 x 10-4 moles) Volume of H2 gas produced 8. Knowing the mass and the number of moles will allow us to compute the molar mass of the liquid: molar mass = (mass)/(number of moles). In conclusion, this lab analyzed the molar relationship between sodium hydroxide and an unknown acid. Determine the pressure of the hydrogen gas at the conditions of this experiment. txt) or view presentation slides online. Molar mass of a gas. Solution: 1) The molar mass of anhydrous Na2SO4 is: 142. The gas was volatilized in a fixed volume at atmospheric pressure in a 99. Revised: June 2005. Demonstrate this by calculating the percent water in each sample. If you dissolve 58. The balanced equation for this reaction shows that the molar ratio of magnesium reacted to hydrogen gas produced is 1:1. The molar mass of unknown gas was found to be 47±6g. This excess molar volume is directly related with the partial […]. Do another determination with a second portion of your unknown. pdf] - Read File Online - Report Abuse. The purpose of this lab is to determine the identity of a Group 1 metal carbonate compound by gravimetric analysis. MOLAR MASS OF A GAS Group Members: _____ _____ _____ _____ As a group, design an experiment to measure the molar mass of the gas in the lighter. This lab was quite long because we had to dry the KHP and the soda ash, and also make in total 9 titrations without taking into account those we messed up and had to re-do to get a better result. The freezing point apparatus consists of a freezing point test tube fitted with a stopper, a digital thermometer and a stirring wire. (OPTIONAL) Calculation of the class average for class STP molar volume determinations: Obtain the experimentally determined STP molar volumes from the other lab teams for an evaluation of how well the mean of the experimental determinations of the STP molar volume agrees with the actual (theoretical) value. DETERMINING THE MOLAR MASS OF CARBON DIOXIDE. T-butyl Alcohol Lab Marquis Cuffee Chem 222 L 12/6/13 Abstract The goals of this experiment were to determine the freezing point of t-butyl alcohol, the molal freezing point constant for t-butyl alcohol, and the molar mass of an unknown substance. perry laboratory assistant name: thomas. In this lab, students determine the molar mass of the volatile liquids ethanol and 2-propanol using the Dumas method. The Ka and Molar Mass of a Monoprotic Weak Acid Chemistry Lab 152 Professor: James Giles November 7, 2012 Abstract: The purpose of this experiment was to determine the pKa, Ka, and molar mass of an unknown acid (#14). All you need to do is multiply the number of each type of atom by its atomic mass (which you can find on the back cover of. Molecular mass of NaCl = 58. Normally this value is reported in terms of energy per mole of the substance, but because we do not yet know the molar mass of the liquid, we will measure it in terms of energy per gram of the substance and compare it to the list of possible sample identities at the bottom of this page, also in those units, in order to identify the liquid. Molar Volume and the Universal Gas Constant 6 of 16 Report for Experiment 54 Name_____ Section_____ Date_____ Molar Volume and the Universal Gas Constant Prelaboratory Questions 1. mm Hg and 28°C. The Dumas method is used to determine the density of each vapor; and then the molar mass is calculated. 004 grams, and the initial moles of copper was 0. if Trial # 1 gives a mass of 240 g/mol and Trial # 2 gives 256 g/mol the average should be reported as 248 8 g. 1353 mol malar mass of unknown: tla0 x 1000 g 1000910 1Z9135. Determine the molar mass from the mass of the unknown and the number of moles of unknown. In conclusion, this lab analyzed the molar relationship between sodium hydroxide and an unknown acid. Make a table similar to figure A to record your measured and calculated data. Molar Mass Determination of a Volatile Liquid A. In step1 above, you calculated the mass of water which was transferred from the round flask to the beaker. AP Chemistry - Molar Mass of Butane Lab. Next determine the moles of carbon dioxide produced (Hint: molar mass of carbon dioxide), the moles of unknown sample (Hint: balanced equation), and then the molar mass of the unknown sample in grams/mole. Use the grams per meter and the length of your piece of ribbon to calculate the mass. Download with Google. or download with email. The balanced equation for this reaction shows that the molar ratio of magnesium reacted to hydrogen gas produced is 1:1. Volume of Water. Report the uncertainty as half of the difference between the two mass measurements (ex. You may enter your answer in the form below the Virtual Lab. 002 M (Reagent volume corrected for blank) Molarity of AgNO 3 = = 1. 00% carbon, 6. Determination of the Molar Volume of Hydrogen Gas To measure the molar volume of hydrogen gas, you need to generate a known number of moles of hydrogen gas, measure its temperature, volume and pressure. Mass of water in flask: g Density of water: gcm-3 at ºC Volume of flask: mL L Trial 1 Trial 2 Trial 3 Trial 4 Mass of flask with foil and vapor (g) Mass of flask with foil w/out vapor (g) Mass of vapor (g) Temperature (ºC) Temperature (K) Molar Mass (MM). N o e l l e r | 3 Experimental Procedure 1. This can be done by producing H 2 gas from the reaction between Mg ribbon and HCl then calculate the pressure of H 2 using Dalton’s law. The freezing point depression can be determined by subtracting the temperature of the solution by the temperature of the water. One atomic mass unit (u) is equal to 1/12 the mass of one atom of carbon-12. The numbers (60. 88, the Ka was found to be 1. The distinguishing feature of commercial polymers is that they have molecular weights far in excess of the entanglement molecular weight of about 10,000 g/mole. 1 Determination*of*the*Mass*Percentage** ofCopperinaPenny* * Introduction* * This*experiment*will*cost*you*one*penny*($0. Experimental Method. During the experiment, you measured the temperature of the water in the beaker (21 o C for my data above), and looked up in the Appendix of the lab manual the density of water at that temperature (0. The freezing points of these solutions, which will contain known amounts of p-dichlorobenzene dissolved in cyclohexane, will be measured. This can be done by producing H Molar Volume Determination Table Trial 1 Trial 2 Trial 3 Mass of magnesium piece (g) 0. ADDITIONAL ASSIGNMENT II: Molar Mass of a Volatile Liquid 1. 00 mL and the mass of the 25. perry laboratory assistant name: thomas. Determine the average molar mass. Be organized. Problem #5: Given that the molar mass of Na2SO4 · nH2O is 322. During the experiment, you measured the temperature of the water in the beaker (21 o C for my data above), and looked up in the Appendix of the lab manual the density of water at that temperature (0. The molecular weight of air was calculated by dividing the sum of the change in mass and the molar mass of helium by the moles of air found, as shown in the sample calculations. The atomic weight of sodium is 22. 1 2 3 mass of KHP (g) 2. Use this DT to determine the Molecular Mass of ethylene glycol. The volume of the gas is equal to the volume of the flask. Thus, the molar volume is also the volume occupied by 6. It is due to the internal friction of molecules and mainly depends on the nature & temperature of the liquid. Done by: Seonlim Lee (Lynn) G. Then, using the variables given, determine the temperature of the gas. , volume and mass of gas produced, etc. Calculate the mass of sugar dissolved from the gum (original mass of gum – final mass of gum). reported, instead of the molar extinction coefficients shown in equation 2. 16 g, a pKa of 7. Complete the Lab Worksheet practice on page 5 for your lab report. to the mass collected for the flask containing residual contents and empty cup. Determine the molar mass of the gas. Relates to chapter 10 of "Chemistry the Central Science, 12th Ed. The average concentration of NaOH solution is M. 3400 g sample of a monoprotic unknown acid was quantitatively transferred to a 50. We then count the number of atoms and multiply it by the individual atomic masses. 1 mL Temperature: 21. 0821 L-atm/mol-K. What we did in a nutshell: Very simple lab, we bubbled butane into a graduated cylinder and measure the displaced water as volume of gas. m = molality of the solution = (moles of solute)/(mass of solvent in kg) K f = molal freezing point depression constant (this constant is solvent dependent) K f (naphthalene) = 6. Print out this page also. Download this page: =>MolecularWeight. This value, along with the known mass of benzoic acid, leads to the molar mass determination. Example: A 1x solution of a compound has a molar concentration of 0. If you are given percent composition, you can directly convert the percentage of each element to grams. To address those concerns, this lab uses an aqueous solution of a green compound (sucrose, C 12 H 22 O 11, 342 g/mole) for determining its molar mass by the freezing-point depression of water. Procedure First, standardize a diluted solution of Sodium Hydroxide (NaOH) with Potassium Hydrogen Phthalate (KHP) in order to find the exact molarity of the basic solution. T-Buty Lab Report. readings until you get 3 determinations within 0. Contents Abstract / Summary. The sample essay on Boiling Point Determination Lab Report deals with a framework of research-based facts, approaches and arguments concerning this theme. Use Hess’s law to calculate the molar enthalpy of reaction (1), the combustion of Mg, which is also the formation reaction of MgO. Lab 2: Determine the Percentage of Water in a Hydrate: The goal of this experiment is to learn how to properly calculate the ratio of salt to water, in a hydrated salt, and to calculate the percentage of water (by mass) within a hydrated salt. Show reaction and then determine the moles of H2 in the gas collecting tube. The method was designed by a French chemist named Jean Baptiste André Dumas, after whom the procedure is now named. An empirical formula of a chemical compound is the ratio of atoms in simplest whole-number terms of each present element in the compound. Student Lab partner: A. Mass of an Unknown Solid by Freezing Point Depression. This lab demonstrated how a titration can be used to measure the concentration of an acid or base in solution, calculate the molar mass of an unknown acid or base, and determine the equilibrium constant of a weak acid (Ka) or weak base (Kb). Let's become familiar with colligative properties and to use them to determine the molar mass of a substance. mass of the unknown metal. 523 g, then you can determine the number of moles in that sample by dividing the actual mass by the molar mass (e. 16 g, a pKa of 7. Placed a preweighed vitamin C tablet in a preweighed Erlenmeyer flask 2. Titration Lab. Analysis of Alum, AlK(SO 4) 2 Every substance has unique characteristics which help to determine the identity of it. Answer: With the Dumas method, molar mass is determined by measuring the mass and the volume of the vapor. 1 M, but the molarity of NaOH went a little bit higher (0. Molar Mass by Freezing Point Depression AP Chemistry Laboratory #5 Catalog No. Before you begin, save this Lab Report Template on your computer as LastNameAPChem3. Clamp the neck of the flask to maintain the flask in the boiling water. Determine the mass in grams of each element in the sample. (Since the atomic mass average of sulfur given above only has 3 decimal places, accuracy can not be determined beyond that point). Add 500 mL of distilled water to your largest beaker (at least 600 mL). Mass of water in flask: g Density of water: gcm-3 at ºC Volume of flask: mL L Trial 1 Trial 2 Trial 3 Trial 4 Mass of flask with foil and vapor (g) Mass of flask with foil w/out vapor (g) Mass of vapor (g) Temperature (ºC) Temperature (K) Molar Mass (MM). Record the answer in your data table. Using only one carbon to every three hydrogens to begin, then carbon and two hydrogens got added until a molar mass which was closest to 67. To find the molar mass of butane, you will collect butane gas by releasing it from a lighter and collecting it over water in a graduated cylinder. Normally this value is reported in terms of energy per mole of the substance, but because we do not yet know the molar mass of the liquid, we will measure it in terms of energy per gram of the substance and compare it to the list of possible sample identities at the bottom of this page, also in those units, in order to identify the liquid. The real cell system in the second lab was a potato. 1 Determination*of*the*Mass*Percentage** ofCopperinaPenny* * Introduction* * This*experiment*will*cost*you*one*penny*($0. 3400 g sample of a monoprotic unknown acid was quantitatively transferred to a 50. Contents Abstract / Summary. Lab - The Molar Mass of Butane Gas, C4H10 Date _____ Purpose: To experimentally determine the molar mass of butane gas. The calculated molar mass was found to be 67. molar mass = (mass)/(number of moles). The freezing point of BHT is first determined, followed by the freezing point of a solution of the known substance dissolved in BHT. Chemistry 20 Lab Manual Chemistry 30 Workbook Experiment 14: Molar Mass of a Gas. Download with Google. The purpose of this experiment is to determine the molar volume of hydrogen gas by. Gravimetric Analysis of Phosphorus in Plant Food. Normally this value is reported in terms of energy per mole of the substance, but because we do not yet know the molar mass of the liquid, we will measure it in terms of energy per gram of the substance and compare it to the list of possible sample identities at the bottom of this page, also in those units, in order to identify the liquid. Complete the Lab Worksheet practice on page 5 for your lab report. These calculations will be necessary before one can determine. and the boiling point of the water/ethylene glycol mixture on your Report Sheet. Mass of empty calorimeter cup (Mc) _____ g 2. Before doing the calculation, you need to determine the precision (standard deviation) of a measurement for each piece of equipment used. Chem Lab Repot. of moles of KHP = Mass of KHP used / Molar mass = 0. Chemistry Video Lab #2 (Tollett - 5th) Blog. Contents Abstract / Summary. We were given the barometric pressure of the room and temperature of the room at the start of the lab by the ta (71F and 752 torr). The method used to determine the mass of the unknown Save Paper; 11 Page; 2694 Words; Unit 5. readings until you get 3 determinations within 0. 6 g/mole The molar mass of the gas mixture was found to be 66. This will be equal to the volume of the vapor in the flask. For example, a molecule has a molecular weight of 180. Materials: 0. Biology Lab Report: Osmosis. This value, along with the known mass of benzoic acid, leads to the molar mass determination. To determine the molar mass of a gas based on a knowledge of its mass, temperature, pressure, and volume. *Molar*Mass*byFreezingPoint*Depression* * Introduction**!! When!a!nonvolatile!solute!!is!dissolvedinasolvent,thefreezingpointofthesolutionislowered. See the attached rubric for guidelines - this lab report has NO HYPOTHESIS. perry laboratory assistant name: thomas. This is used to find the unknown substances by doing precipitation reactions. molarity of the stock solution in the lab report). Determine the percent (m/m) of ascorbic acid in a vitamin C tablet 5. pptx), PDF File (. Molar Mass of a Vapor OBJECTIVES To observe how changes in pressure, for a fixed amount of a trapped gas at constant temperature, can affect the volume of the gas. pdf Determination of Molecular Weight. 98 g Volume of Erlenmeyer flask (to line): 276. 079 = molar mass of sulfuric acid. 01 g 1 mol • Your and your lab partner will be assigned either an element or a compound. 99802 g/mL at 21 o C). Digication ePortfolio :: General Chemistry (Alexander Antonopoulos) by Alexander P. 3, which uses Dalton's law. Divide the mass of the water lost by the mass of hydrate and multiply by 100. 32 g/mol Palmitic acid 256. 1 Determination*of*the*Mass*Percentage** ofCopperinaPenny* * Introduction* * This*experiment*will*cost*you*one*penny*($0. From the columes and molarities used, you can calculate. However, it is difficult to find the mass of a gas. The calculated pressure can then be used to find the molar volume of H 2 using the ideal gas equation. Using only one carbon to every three hydrogens to begin, then carbon and two hydrogens got added until a molar mass which was closest to 67. Purpose: The purpose of this lab is to determine the molar volume of H 2 at room temperature and standard pressure. 0987 g Volume used (first equivalence point) = 10. The composition of the product can be estimated by assuming a linear relation between refractive index and molar concentration.