Question

an atmospheric sample is composed of nitrogen, oxygen, argon, and traces of other gases. if the partial pressure of nitrogen is 587 torr, oxygen is 158 torr, and argon is 7 torr, what is the observed barometric pressure?
○ 752 torr
○ 1512 torr
○ 8 torr
○ 422 torr
○ 100 torr

Explanation:

Step1: Recall Dalton's Law

Dalton's Law of Partial Pressures states that the total pressure of a gas mixture is the sum of the partial pressures of its components. So, \( P_{\text{total}} = P_{\text{N}_2} + P_{\text{O}_2} + P_{\text{Ar}} + P_{\text{others}} \). But since the other gases are traces, we can assume their partial pressure is negligible or we just sum the given ones (nitrogen, oxygen, argon) as a start. Wait, actually, the problem gives nitrogen (587 torr), oxygen (158 torr), argon (7 torr). So we sum these.

Step2: Calculate Total Pressure

\( P_{\text{total}} = 587 + 158 + 7 \)
First, \( 587 + 158 = 745 \)
Then, \( 745 + 7 = 752 \) torr.

Answer:

752 torr (the option: 752 torr)