How many grams of chlorine reacted with potassium iodide if 50.8 g of iodine was formed?

Let’s write the reaction equation:

2KI + Cl2 = 2KCl + I2

Let’s find the amount of iodine substance:

v (I2) = m (I2) / M (I2) = 50.8 / 254 = 0.2 (mol).

According to the reaction equation, 1 mol of I2 is formed per 1 mol of Cl2, therefore:

v (Cl2) = v (I2) = 0.2 (mol).

Thus, the mass of reacted chlorine is:

m (Cl2) = v (Cl2) * M (Cl2) = 0.2 * 71 = 14.2 (g).

Answer: 14.2 g.