Sulfur (4) oxide was passed through the solution, which contains 11.6 potassium hydroxide
Sulfur (4) oxide was passed through the solution, which contains 11.6 potassium hydroxide, until the alkali was completely neutralized. What is the mass and amount of salt substances that have turned out?
Given:
m (KOH) = 11.6 g
To find:
m (salt) -?
n (salt) -?
Solution:
1) 2KOH + SO2 => K2SO3 + H2O;
2) M (KOH) = Mr (KOH) = Ar (K) * N (K) + Ar (O) * N (O) + Ar (H) * N (H) = 39 * 1 + 16 * 1 + 1 * 1 = 56 g / mol;
M (K2SO3) = Mr (K2SO3) = Ar (K) * N (K) + Ar (S) * N (S) + Ar (O) * N (O) = 39 * 2 + 32 * 1 + 16 * 3 = 158 g / mol;
3) n (KOH) = m (KOH) / M (KOH) = 11.6 / 56 = 0.2 mol;
4) n (K2SO3) = n (KOH) / 2 = 0.2 / 2 = 0.1 mol;
5) m (K2SO3) = n (K2SO3) * M (K2SO3) = 0.1 * 158 = 15.8 g.
Answer: The mass of K2SO3 is 15.8 g; the amount of substance is 0.1 mol.