# What is the molarity of a solution in 200 ml of which contains 25 g of naoh?

March 29, 2021 | education

| In order to calculate the molarity of the solution, we calculate the amount of substance in the available mass of alkali.

To do this, we find the ratio of the weight of the substance to the weight of one mole.

Its molar weight will be:

M NaOH = 23 + 16 + 1 = 40 grams / mol;

The amount of the substance will be:

N NaOH = 25/40 = 0.625 mol;

Let’s calculate the molarity of the solution.

200 ml contains 0.625 mol of base. One liter of such a solution contains 0.625 x 1000/200 = 3.125 mol of base. The solution has a molarity of 3.125 M.