Question

Which best defines partial pressure in a mixture of gases?
pressure that is exerted by all the gases of a mixture on the container
pressure that is exerted by one gas as if it occupied a container by itself
half of the pressure that is exerted by the gases of a mixture on the container
sum of the individual pressures that are exerted by two or more gases

Answer 1

"pressure that is exerted by one gas as if it occupied a container by itself"

Explanation: In a gas mixture each component exerts a partial pressure equal to the pressure it would have alone in the same volume and temperature. The total pressure is the sum of the partial pressures (Dalton's law).