How much water should be added to 200 g of a 20% salt solution to make the salt concentration in the solution 16%?

1.Let’s find the mass of salt in solution by the formula:

W = m (substance): m (solution) × 100%,

hence m (substance) = (m (solution) × w): 100%.

m (salt) = (200 g x 20%): 100% = 40 g.

Or:

200 g – 100%,

X- 20%,

X = (200g x 20%): 100% = 40g.

2. Find the mass of the solution.

W = m (substance): m (solution) × 100%,

hence m (solution) = (m (substance): W) × 100%,

m (solution) = (40 g: 16%) × 100% = 250 g.

m (solution) = m (water) + m (substance).

Hence m (water) = m (solution) – m (substance).

m (water) = 250 g – 40 g = 210 g.

Answer: 210 g.