**What is Mass per cent?**

Mass per cent is a way of expressing a concentration or describing the component in a particular mixture. The solution composition can be described in mass percentage which shows the mass of solute present in a given mass of solution. The quantity of solute is expressed in mass or by moles. For a solution, the mass per cent is described as the grams of solute per grams of solution, multiplied by 100 to get the percentage.

**Mass per cent Formula**

The Mass per cent formula is expressed as solving for the molar mass also for the mass of each element in 1 mole of the compound. You can determine the mass percentage of each element with these masses.

**Example 1**

**An aqueous solution of sodium chloride (CaCl2) is prepared. Determine the mass of 5%(m/m) solution of calcium chloride that can be prepared using 100 g of calcium chloride.**

**Solution**

The interpretation of mass/mass per cent number shows that 5g of CaCl2 is used to prepare 100g of solution.

Therefore,

g solution = (100g CaCl2 x 100g solution) / 5g CaCl2

g solution = 2 x 10^{3} g solution

Hence, 2 x 10^{3} g of 5% (m /m) solution can be prepared using 100g CaCl2

**Example 2**

**Determine how many grams of sugar is present in 1.500g pf 1.50% solution of sugar in water.**

**Solution**

Since mass percentage gives the mass of sugar in 100g of solution.

The two conversion factors can be solved as follows,

1.50g sugar / 100g solution are inverted to 100g solution / 1.50g sugar

the given solution by the first conversion

G sugar = (1.500g solution x 1.5g solution) / 100g solution

G sugar = 22.5g sugar

Hence, 22.5g sugar is present in 1.500g of 1.50% solution.

## Comments