please give two applications of daltons law of partial pressure.please reply fast i have an exam coming sooon ..please reply asap:)

1. This law is can be used to find the mole fraction of a gas in a mixture of gases

Mole fraction of a gas = partial pressure of the gas/ total pressure

2. This law can be used to find the partial pressure of the dry gas collected over water.The gas collected over water becomes moist due to the water vapours.The total pressure exerted by the moist gas is equal to the sum of partial pressures of dry gas + aqueous tension (pressure due to water vapour).Since the aqueous tension is constant  at constant temperature, partial pressure of the dry gas can be determined as follows:

P(dry gas) = total pressure – aqueous tension.