Question

Which of the following gases has the highest density at STP?

• A. \( \text{O}_2 \)
• B. \( \text{N}_2 \)
• C. \( \text{CO}_2 \)
• D. \( \text{H}_2 \)

Hint:

Remember: At STP, the density of a gas is directly related to its molar mass. A higher molar mass leads to a higher density.

Answer 1

The Correct Option is C

Step 1: Understand the relationship between molecular weight and density At STP (Standard Temperature and Pressure), the density of a gas is directly related to its molar mass. The greater the molar mass, the higher the density. Step 2: Molar masses of the gases The molar masses of the gases are as follows: - \( \text{O}_2 \): \( 32 \, \text{g/mol} \), - \( \text{N}_2 \): \( 28 \, \text{g/mol} \), - \( \text{CO}_2 \): \( 44 \, \text{g/mol} \), - \( \text{H}_2 \): \( 2 \, \text{g/mol} \). Step 3: Compare the densities - \( \text{CO}_2 \) has the highest molar mass, which means it will have the highest density at STP. Answer: The correct answer is option (3): \( \text{CO}_2 \).