Question

A lab assistant wants to prepare 0.2 mol dm-³ of potassium chloride solution. What is the volume of distilled water needed to dissolve 2.98 g of potassium chloride? [Molar mass of potassium chloride = 74.5 g mol-¹]​

Answer 1

Step-by-step explanation:

Molarity given = 0.2 mol dm ^ -3

wieght of potassium chloride = 2.98g

molar mass of potassium cloride = 74.5

let us assume vol. of water needed= x

molarity = weight * 1000 / molar mass * volume

0.2 = 2.98 * 1000 / 74.5 * x

0.2 = 2980 / 74.5x

74.5x = 2980 / 0.2

74.5 x = 14900

x = 200

hence, volume required is 200 ml