Concentrating a Solution Calculator

Solve classic salt-water word problems about making a solution stronger, with clear steps.

Input

Choose how to concentrate the solution, then enter the original mass and concentration.

Operation

Original solution mass

Original concentration

Salt to add

Mass of salt added to the solution.

Concentration after adding

13.64 %

Salt after

30 g

Total mass after

220 g

Concentration after

13.64 %

How to solve it

The salt in the original 200 g at 5 percent is 200 times 5 divided by 100, which is 10 g.

Adding 20 g of salt gives 30 g of salt and 220 g in total.

The concentration is 30 divided by 220 times 100, which is 13.64 percent.

The mass of salt in a solution equals the total mass times the concentration divided by 100.
The key idea is to track which quantity stays fixed and which one changes as you concentrate the solution.
When you add salt, both the salt and the total mass increase by the same amount. The new concentration is the new salt divided by the new total mass, times 100.
To reach a target concentration by adding salt, choose the amount so the salt makes up the target fraction of the new total.
When you evaporate water, the salt mass stays the same and only the total mass decreases. Choose the evaporated amount so the unchanged salt is the target fraction of the smaller total.
The target concentration must be higher than the original concentration and below 100 percent.

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