Question

Which of the following is NOT true at high altitude?

a) The partial pressure of carbon dioxide is lower.

b) The partial pressure of oxygen is lower.

c) The proportion of gas molecules that are oxygen molecules is lower.

d) The total pressure is lower.

Answer 1

Option C is incorrect.

Total amount of air at high altitude is lower than that at the sea level.

Due to decreased amount of air, the total pressure of air is also lower at high altitudes.

Similarly, partial presurre of individual gases like oxygen and carbon dioxide is also lower, because their amount is less in high altitudes.

But, the proportion of gases is same, even at high altitudes.This means that if oxygen constitutes 21 % of total air at sea level, then it will constitute 21% of air, even at high altitudes.