What is the equation that gives percentage purity in terms of the mass of the pure chemical and the mass of the sample?
A mixture of nitrogen and oxygen gas has a mass of 1.20 kg. After 250 g of oxygen in the mixture is reacted with a metal, pure nitrogen is left behind. To 2 significant figures, what is the percentage purity of nitrogen in the original mixture?
An impure sample of aluminum bromide contains 4% contaminants by weight. What is the percentage purity of the sample?