# Calculate the mass fraction of sodium hydroxide and the volume of water required to prepare 400

Calculate the mass fraction of sodium hydroxide and the volume of water required to prepare 400 grams of an alkali solution with a mass fraction of NaOH of 10%.

The mass of the alkali solution is 400 grams;

To find the mass of alkali, it is necessary to multiply its mass fraction by the mass of the solution.

m of alkali = 400 x 0.1 = 40 grams;

To find the mass of water, it is necessary to subtract the mass of alkali from the mass of the solution:

m of water = 400 – 40 = 360 grams;

The density of water is 1 gram / cm3. To prepare this solution, measure 360 ml of water.

Check: 360 + 40 = 400;

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.