How many grams of potassium hydroxide will result from the interaction of 47 g of potassium oxide with water?

Let us write the equation for the reaction of potassium oxide with water:
K2O + H2O = 2KOH
Let’s write an expression to determine the amount of a substance:
ν = m / M = V / Vm
Let’s equalize the expressions for the amount of substance:
m (K2O) / M (K2O) = m (KOH) / (2 * M (KOH))
Let’s define the molar masses:
M (K2O) = 39 * 2 + 16 = 94 g / mol.
M (KOH) = 39 + 16 + 1 = 56 g / mol.
Let us express the mass of potassium hydroxide from the equation:
m (KOH) = m (K2O) * 2 * M (KOH) / M (K2O)
Substitute the numerical values:
m (KOH) = m (K2O) * 2 * M (KOH) / M (K2O) = 47 * 2 * 56/94 = 56 g.
Answer: you get 56 g of potassium hydroxide.