Lab Report: determine the molar mass of an unknown gas, from the gas density

PURPOSE : In this particular laboratory experiment, we are going to determine the molar mass of an unknown gas, from the gas density. We are also going to use gas density, along with the kinetic molecular theory, to explain the behavior of gas filled balloons. Finally, we are going to demonstrate the effects of temperature and pressure changes of gasses.

PROCEDURE : We are using the experimental procedure as described in our laboratory manual.

University of Wisconsin - River Falls

Laboratory Manual

Chemistry 116

Experiment 116-8

Molar Mass From Gas Densities

Pages 81 & 82

There are no changes to this laboratory or from the indicated laboratory procedure.

MATERIALS and APPARATUS :

Part A-1: In this part of the experiment, we are going to observe three balloons filled each with one of three different gasses. So as part of our materials we need to have three balloons as well as the three gasses.

Experiment

Global Carbon Dioxide 2002-2009, with Mauna Loa Ca...

ball-and-stick model of CO2: carbon dioxide

These balloons were already prepared for us and we kept underneath the fume hood for observation.

Helium Sulfur Exofluoride

He SF6

4.002602 g. 146.06 g.

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Ammonia

NH3

17.031 g.

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Part A-2-5c: During this part of the experiment, our materials and equipment consisted of one, clean, dry, 500mL plastic bottle with an airtight cover. Along with the bottle we need an electronic balance, a thermometer set up to measure the air temperature, as well as a barometer with a chart on how to interpret the readings. Finally we must have the six different gasses with which to do our experiment.

Distilled Water Helium

H2O He

33.00674 g. 4.002602 g.

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Oxygen Argon

O2 Ar

31.9988 g. 39.948 g.

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Carbon Dioxide Propane

CO2 CH3CH2CH3

44.0098 g. 44.09652 g.

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Natural Gas

CH4

16.04276...