Question

How many grams of potassium chloride are needed to make 1L of a 0.400M potassium chloride solution

Answer 1

MM(KCl) = 74.55 g/mol

In order to make 1 L of 0.400 M potassium chloride solution we need 0.4 mol of KCl.

$m = n \times MM \\ = 0.4 \times 74.55 = 29.82 \;g$

Answer: 29.82 g