ࡱ;   R F F=@CompObj\WordDocument3 ObjectPool F= F= FMicrosoft Word 6.0 DocumentNB6WWord.Document.6;  Oh+'0  ! -9A IUr z5Science F:Microsoft Office:Microsoft Word 6:chem labLAB: TITLE OF LABsciencescience'@qB=@"UE=@E=@ܥhO e= 3 R 4VVVVV(~ VV&tXg @ 6Lab: the molecular weight of a compoound  Introduction In this lab, we will determine the vapor density of a volatile liquid at standard conditions. We will then combine the vapor density with molar volume to determine the molar mass of the volatile liquid. MATERIALS: 125 mL erlenmeyer flask iron ring large beaker into which the flask can fit wire gauze small square of aluminum foil clamp pin thermometer ring stand bunsen burner Procedure 1. Obtain the mass of a clean dry 125-mL erlenmeyer flask. 2. Pour 2 - 3 mL of the uncknown liquid into the flask. 3. Place the aluminum over the top of the flask and make a small pin hole in the foil. 4. Place flask into the beaker and fill the beaker with water. Put the beaker on the iron ring/wire gauze on the ring stand. Clamp the flask to the ring stand. 5. Only after this is completely assembled will you now light the bunsen burner. Heat the water until the unknown liquid evaporates. Take the temperature of the water bath. 6. When the last bit of liquid evaporates, remove the flask from the boiling water by holding the clamp. Hold the flask , tilted sideways, under cold running water for about a minute. This will condense any vapor in the flask back into liquid. 7. Now dry the outside of the flask completely, remove the foil and weigh the flask again. 8. Fill the flask to the very top with water. Pour the water into a large graduated cylinder to obtain its volume. 9. Read the barometric pressure for today Data MASS OF FLASK EMPTYMASS OF FLASK WITH CONDENSED LIQUIDVOLUME OF FLASKTEMPERATURE OF HOT WATERBAROMETRIC PRESSURE Calculations 1. CALCULATION OF THE DENSITY OF THE VAPOR AT STP (G/L) a. Subtract the mass of the empty flask from the mass of the flask containing the condensed liquid to obtain the mass of the condensed material. b. Convert the volume of the flask at lab conditions to STP. (Consider that the vapor occupied this volume in the boiling water.) c. Calculate the density of the vapor at STP in g/L. 2. CALCULATION OF MOLAR MASS (g/m). a. Knowing the density of the vapor at STP (g/L) and the molar volume (L/m), calculate the molar mass (g/m). 3. Calculate the percent error . The teacher will supply you with the actual molar mass. Analysis Write a conclusion. GASES Name: _______________________ Partner #1: _______________________ Partner #2: _______________________ Acton-Boxborough Regional High School Due Date: ______________________ Acton-Boxborough Regional High School ?|HH(EG(HH(d'p|HH(EG(HH(d'p |HH(EG(HH(d'p00&ta0`0(00&00&00&00&00&ࡱ; SummaryInformation(Microsoft Word 6.0.15ࡱ; )*+,-:j k l z   & Q R T Z  8 < = uU]cU]c]uD]a UZ]c( UZ]c(*,:;8oIBC  % & ' 7 8 $$$,$$$$$$$$$$$$,$,$,,,,,,,,,lH$ h&8 9 R S T h i j k y z  N O P    B C        ,,,,,,,$$,$$$$$$$$$$$$$$$$$$$$$$$$$lH$ lH$ $ & ' ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T x $,$$$$$$$$$$$$$$$$$$$$$$$$$$$T$T 0 !l h !s0h !sh$       : ; < = $h 0 !l K@Normal]a "A@"Default Paragraph Font @ Header ! @ Footer !*O"* Chem HeaderL UZ]c= = O   \n= qs  8  = *,k = Jzscience/Science F:Teacher Folders:Murphree:MOLAR VOLUMEscience-Science F:Teacher Folders:Murphree:MOLAR MASSscience-Science F:Teacher Folders:Murphree:MOLAR MASSscience-Science F:Teacher Folders:Murphree:MOLAR MASSscience-Science F:Teacher Folders:Murphree:MOLAR MASS@ &VMTimes New Roman Symbol MArial MTimesMNew Century Schlbk"1hLZ1&eZ1&_Z1&9g4Science F:Microsoft Office:Microsoft Word 6:chem labLAB: TITLE OF LABsciencescienceࡱ;