Determine the mass fraction of a substance in a solution if it is known that 19 g

Determine the mass fraction of a substance in a solution if it is known that 19 g of barium hydroxide was dissolved in 500 g of water.

Given:

m (substance) = 19 g,

m (water) = 500 g.

W (substances) -?

Decision :

Mass fraction of a substance is calculated by the formula:

W = m (substance): m (solution) × 100%,

m (solution) = m (substance) + m (water).

Let’s find the mass of the solution.

500 g + 19 g = 519 g.

Let’s find the mass fraction of the substance in the solution.

W = (19g: 519g) × 100% = 3.661%.

Answer: Mass fraction of barium hydroxide is 3.661%.