General Chemistry 1: Solutions and Molality

A solution contains 30% w/w NH##_3## (aq) (density: 0.90 g/mL). Find the molarity of the solution.

A solution contains 30% w/w NH##_3## (aq) (density: 0.90 g/mL). Find the mole fraction of the solution.

What is the mole percent and fraction of each component of a mixture composed of 0.200 mol O##_2## and 0.500 mol N##_2## ?

Calculate the mole fraction (and mole percent) of oxygen in exhaled air if the P##_{O_2}## = 760 torr and P##_{total}## is 1116 torr.