Calculate how much water is required to prepare a 25% sodium chloride solution, if you take 45 g of salt.

In this solution, 45 grams of salt will have a mass fraction of 25%.
Determine the weight of the solution. To do this, divide the weight of water by its mass fraction.
M solution = M salt / C salt = 45 / 0.25 = 180 grams;
Let’s find the weight of the salt.
To do this, subtract the weight of the salt from the weight of the solution.
M water = M solution – M salt = 180 – 45 = 135 grams;
Let’s check:
45 + 135 = 180;