Question

1. A gas at a pressure of 605 mmHg is held in a container with a volume of 624 mL.
The volume of the container is then increased to 1222 mL without a change in
temperature. What is the new pressure of the gas?
2. A person using oxygen mask is breathing air with 32% O2. What is the partial
pressure of the O2 when the air pressure in the mask is 120 000 Pa?
3. If a gas is cooled from 100°C to 25°C and the volume is kept constant, determine the change in pressure that would result if the original pressure was 758.0 mmHg.
4. If helium in a sealed container is pressurized from 10.0 atmospheres to 15.0
atmospheres and its original temperature is 40°C, what will the final temperature (in
Celsius) of the gas be?

Answer 1

Answer:

The partial pressure of hydrogen gas

P

′

=

V

′

PV

=

1

0.8×0.5

=0.40 bar

(ii) The partial pressure of oxygen gas

P

′′

=

V

′

PV

=

1

0.7×2.0

=1.40 bar

So, the total pressure of gaseous mixture is P+P

′′

=0.40+1.40=1.80 bar