Question

The molar mass of KCl is 74.55 g/mol. If 8.45 g KCl are dissolved in 0.750 L of solution, what is the molarity of the solution?

Answer 1

Moles of KCl = 8.45/74.55 = 0.1133moles. Molarity = moles of KCl/ volume of solution in litres = 0.1133/0.75 = 0.151M.

Answer 2

Answer:

                  Molarity  =  0.1516 mol.L⁻¹

Solution:

             Molarity is the amount of solute dissolved per unit volume of solution. It is expressed as,

                         Molarity  =  Moles / Volume of Solution    ----- (1)

Data Given;

                  Mass  =  8.45 g

                  Volume  =  0.750 L

Step 1: Calculate Moles for given mass as,

                   Moles  =  Mass / M.mass

                   Moles  =  8.45 g / 74.55 g.mol⁻¹

                   Moles  =  0.1133 mol

Step 2: Calculating Molarity:

Now, putting value of Moles and Volume in eq. 1,

                        Molarity  =  0.1133 mol ÷ 0.750 L

                        Molarity  =  0.1516 mol.L⁻¹