Percent Composition and Solubility

A solute is a substance that is dissolved in a solvent to form a solution. For example, sugar is the solute when dissolved in water.

Percent composition = (mass of element in 1 mole of compound / molar mass of compound) x 100%.

The molar mass of CO is approximately 28 g/mol (12 g/mol for C and 16 g/mol for O).

Percent composition of carbon in CO = (12 g/mol / 28 g/mol) x 100% = 43%.

Solubility is the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature.

The solubility of NaBr at 70 degrees Celsius is 120 g per 100 g of water.

The molar mass of MgBr2 is approximately 200.89 g/mol (24.31 g/mol for Mg and 79.9 g/mol for each Br).

Percent composition of magnesium in MgBr2 = (24.31 g/mol / 200.89 g/mol) x 100% = 12.1%.

Solubility curves graphically represent how the solubility of a substance changes with temperature.

Yb2(SO4)3 has the lowest solubility at 30°C.