Answer to Question #310352 in Chemistry for sael

Question

A sample of O2 was collected over water at 23˚C and 760 torr. What is the partial pressure O2 at the given temperature and pressure? The vapor pressure of water at 23˚C is 21.2 torr.

Answer 1

Solution:

Dalton's law can be used: "the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases in the mixture".

This is shown by the equation:

P_total = P₁ + P₂ + ... + P_n

P_total = 760 torr

P_oxygen = unknown

P_water = 21.2 torr

Thus,

P_oxygen = P_total − P_water = 760 torr − 21.2 torr = 738.8 torr

P_oxygen = 738.8 torr

Answer: The partial pressure O₂ is 738.8 torr