In water, weighing 100 grams. 108.7 g of sodium hydroxide dissolves at a temperature of 20 C. What mass of NaOH

In water, weighing 100 grams. 108.7 g of sodium hydroxide dissolves at a temperature of 20 C. What mass of NaOH and water should be taken to prepare a saturated alkali solution weighing 40 g at a temperature of 20 C?

Let’s calculate the concentration of alkali in a saturated solution.

m solution = 100 + 108.7 = 208.7 grams;

The alkali concentration will be:

With alkali = 108.7 / 208.7 = 0.52 = 52%;

Based on these data, we find the mass of alkali and water in 40 grams of a saturated solution.

m of alkali = 40 x 0.52 = 20.8 grams;

m of water = 40 – 20.8 = 19.2 grams;

Check: 20.8 + 19.2 = 40;