At the top of a mountain, the total pressure of the air is 380 mm Hg…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
At the top of a mountain, the total pressure of the air is mm Hg. The air is still per cent oxygen.
- Find the partial pressure of oxygen at the top.
- Express it as a per cent of the sea level value of mm Hg.
Need a reminder? The key ideaShow
The partial pressure of a gas is its share of the total pressure: . Gases diffuse from the higher partial pressure to the lower one. The rate depends on the gradient, the solubility of the gas and the thickness of the membrane. Carbon dioxide is to times more soluble than oxygen.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. Total pressure: mm Hg. Oxygen: per cent.
Plan. Find the share of the total pressure, then compare it with the sea level value.
Step 1. Partial pressure. mm Hg.
Step 2. Compare. .
Answer: mm Hg, which is of the value at sea level.
Check. The pressure is half of mm Hg, so the pO is half as well.
Watch out. The air at the top still has per cent oxygen. It is the pressure that is lower.
Discussion (0)
Log in to join the discussion.
Loading…