Determine the mass of a 10% potassium hydroxide solution that will be required

Determine the mass of a 10% potassium hydroxide solution that will be required for the reaction with iron (II) sulfate if 9 g of precipitate is formed.

Given:
w (KOH) = 10% = 0.1
m (Fe (OH) 2) = 9 g
To find:
m solution (KOH)
Decision:
2KOH + FeSO4 = K2SO4 + Fe (OH) 2
n (Fe (OH) 2) = m / M = 9 g / 90 g / mol = 0.1 mol
n (Fe (OH) 2): n (KOH) = 1: 2
n (KOH) = 0.1 mol * 2 = 0.2 mol
m in islands (KOH) = n * M = 0.2 mol * 56 g / mol = 11.2 g
m solution (KOH) = m in-va / w = 11.2 g / 0.1 = 112 g
Answer: 112 g