In order to make a 500 cm³ solution of potassium chloride, concentration 2 mol dm^-3, what mass (in g) of potassium chloride must be dissolved in water?

Question

Quizplus · Accepted Answer

First, we need to convert the concentration from mol dm^-3 to g dm^-3, so we use the formula:

mass = concentration x molar mass

The molar mass of potassium chloride (KCl) is 74.55 g/mol, so:

mass = 2 mol dm^-3 x 74.55 g/mol
mass = 149.10 g dm^-3

To make a 500 cm^3 solution, we need to calculate the mass of KCl required:

mass = volume x concentration
mass = 500 cm^3 x 149.10 g dm^-3 / 1000 cm^3 dm^-3
mass = 74.55 g

Therefore, the answer is D, 74.55 g of KCl must be dissolved in water.

In Order to Make a 500 Cm3 Solution of Potassium

In Order to Make a 500 Cm³ Solution of Potassium