I missed class and need help filling this out Pre-Lab Questions: Experiment 8-Mo

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I missed class and need help filling this out

Pre-Lab Questions: Experiment 8-Molar Mass of a Volatile Liquid Name SHOW ALL OF YOUR WORK TO RECEIVE FULL CREDIT!!! 1. Use the data below to answer the following questions. ass of flask, foil, and tie: 21.417 g Massof flask, foil, tie, and vapor: 21.685 g Temperature of the boiling water: 98.9°C Volume of Erlenmeyer flask: 132 mL Barometric pressure: 755 mmHg a. What is the temperature of the vapor in Kelvin? b. What is the volume of the vapor in liters? c. What is the pressure of the vapor in atmospheres? d. Calculate the mass of the vapor. e. Determine the molar mass of the vapor. 2. Briefly explain what would happen to the molar mass if you left the temperature in degrees Celsius.

Explanation / Answer

In this method , we find the the molar mass of substance by vaporising the known mass of substance , by using the ideal gas equation we can calculate the molar mass.

a)temperature of the boiling water = 98.9 C = 98.9 + 273.15

= 372.05 K

b)V of vapor = 132 mL = 0.132 L

c)P of vapor = 755mmHg = 755/760 atm

d)mass of sample = 0.268 g

R = 0.0821L.atm/mol.K

e) using PV = (mass/Molarmass) RT and substituting the values

( 755/760 atm ) x0.132L = (0.268/molar mass) 0.0821L.atm/K.mol x 372.05K

molar mass of sample = 62.43 g /mol

2) If the temperature were taken in C as 98.9 , the molar mass of the sample would very small value (=16.59)

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