Multiple choice

A closed vessel contains 8 gm of oxgen 7 gm of nitrogen and 1 gm of hydrogen. The total pressure is 8 atmospheres at a given temperature. If now oxygen is removed without change in temperature the pressure of the remaining gas is

  1. 3 atm

  2. 4 atm

  3. 5 atm

  4. 6 atm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Partial pressure is proportional to the number of moles. Moles: O2 = 8/32 = 0.25, N2 = 7/28 = 0.25, H2 = 1/2 = 0.5. Total moles = 1.0. Total pressure = 8 atm. Pressure per mole = 8 atm. Removing O2 (0.25 moles) leaves 0.75 moles. Remaining pressure = 0.75 * 8 = 6 atm.

AI explanation

The pressure of a gas mixture is proportional to the total number of moles present at a constant temperature and volume. The moles of oxygen are 8 divided by 32, which is 0.25 moles, while the combined moles of the other gases are 7 divided by 28 plus 1 divided by 1, equaling 1.25 moles. The initial total moles are 1.5, so removing oxygen leaves 1.25 moles, and the final pressure is 8 multiplied by (1.25 divided by 1.5), which equals 6 atm.

Keep practicing — related questions