What masses of salt and water do you need to take to prepare 500 grams of a 9% solution?

Given:
m solution (salt) = 500 g
ω (salt) = 9%

Find:
m (salt) -?
m (water) -?

Solution:
1) Calculate the mass of salt in the solution:
m (salt) = ω (salt) * m solution (salt) / 100% = 9% * 500/100% = 45 g;
2) Calculate the mass of water in the solution:
m (water) = m solution (salt) – m (salt) = 500 – 45 = 455 g.

Answer: The mass of salt in solution is 45 g; the mass of water in solution is 455 g.