What is the concentration of the resulting solution when mixing 200 grams of 15% solution

What is the concentration of the resulting solution when mixing 200 grams of 15% solution with 150 grams of 20% sodium chloride solution?

Given:

m (first solution) = 200 g

m (second solution) = 150 g

w% (first solution) = 15%

w% (second solution) = 20%

To find:

w% (salts in the final solution) -?

Solution:

1) Find the mass of the solution obtained by merging:

m (solution) = 200 g + 150 g = 350 g;

2) Find the masses of salt in both solutions:

m1 (salt) = 200 g * 0.15 = 30 g

m2 (salt) = 150 g * 0.2 = 30 g

3) Find the mass of salt after draining the solutions:

m (salt) = 30 g + 30 g = 60 g;

4) Find the concentration of salt in the resulting solution:

w% (salt) = m (salt): m (solution) * 100% = 60 g: 350 g * 100% = 17.14%.

Answer: w% (salts) = 17.14%.