To 50 g of a 10% solution of acetic acid was added 70 g of a 20% solution

To 50 g of a 10% solution of acetic acid was added 70 g of a 20% solution of the same acid. the mass fraction of sulfuric acid in the resulting solution is …

Given:

m (first solution CH3COOH) = 50 g

w% (CH3COOH) = 10%

m (second solution CH3COOH) = 70 g

w% (CH3COOH) = 20%

To find:

w% (CH3COOH in the final solution) -?

Decision:

1) Find the mass of acid in both solutions:

m1 (CH3COOH) = 50 g * 0.1 = 5 g

m2 (CH3COOH) = 70 g * 0.2 = 14 g;

2) Find the total mass of acid in the new solution:

m (CH3COOH) = 5 g + 14 g = 19 g;

3) Find the mass of the solution after draining:

m (solution) = 50 g + 70 g = 120 g;

4) Find the mass fraction of acetic acid in the new solution:

w% (CH3COOH) = m (CH3COOH: m (solution) * 100% = 19 g: 120 g * 100% = 15.83%.

Answer: w% (CH3COOH) = 15.83%.