How many grams of KOH is needed to prepare 2 liters of 0.1 N potassium hydroxide solution?

Given:
V solution (KOH) = 2 l
SN (KOH) = 0.1 n

To find:
m (KOH) -?

Solution:
1) Calculate the amount of potassium hydroxide substance:
n (KOH) = CH (KOH) * V solution (KOH) / z = 0.1 * 2/1 = 0.2 mol;
2) Using the periodic system of D.I.Mendeleev, calculate the molar mass of potassium hydroxide:
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;
3) Calculate the mass of potassium hydroxide:
m (KOH) = n (KOH) * M (KOH) = 0.2 * 56 = 11.2 g.

Answer: The mass of KOH is 11.2 g.