If 50.0cm3of a saturated solution of KNO3at 40oC contained 5.05g of the salt. What is the solubility of the salt at 40oC? [KNO3=101].

The solubility of KNO₃ at 40° C is 1 mol/dm³

Explanation:

The solubility of a substance is the number of moles of that substance (solute)  contained in a unit volume of solvent at that particular temperature.

Now, Solubility = n/V where n = number of moles of KNO₃ and V = volume of saturated solution = 50.0 cm³ = 0.05 dm³

n = m/M where m = mass of KNO₃ = 5.05 g and M = molar mass of KNO₃ = 101 g/mol

n = 5.05 g/101 g/mol = 0.05 mol

Solubility = n/V

= 0.05 mol/0.05 dm³

= 1 mol/dm³

So, the solubility of KNO₃ at 40° C is 1 mol/dm³