Chemistry 9th Edition

Published by Cengage Learning
ISBN 10: 1133611095
ISBN 13: 978-1-13361-109-7

Chapter 5 - Gases - Questions: 27

Answer

The molar volume of $N_2$ at STP is 22.42 L/mol $N_2$. This is calculated through the ideal gas law. The molar volume of He at STP is equal to the molar volume of $N_2$ at STP. The molar volume of $N_2$ is greater than 22.42 L/mol at 1.000 atm and 25.0 degrees Celsius. The molar volume of $N_2$ collected over water is less than 22.42 L/mol.

Work Step by Step

$PV=nRT\Rightarrow \frac{V}{n}=\frac{RT}{P}\Rightarrow \frac{V}{n}=\frac{273*0.08206}{1.000}=22.42 \text{ L/mol}$ Because pressure and temperature are equal, the two gases have an equal molar volume. $\frac{P}{V}=\frac{293*0.08206}{1.000}=24.04>22.42 \text{ L\mol}$ Because $N_2$ is collected over water, part of the 1.000 atm pressure is due to the evaporation of water. Therefore, the partial pressure of $N_2$ is less than 1.000 atm thereby proving the molar volume is less than 22.42 L. On the other hand, if the partial pressure of $N_2$ was 1.000 atm, then the molar volume would be 22.42 L in this scenario.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.