Question

Calculate the molarity of a 50.0mL of a 0.150M HCL solution when 30.0mL of water is added.

Answer 1

Molarity = moles of solute / liters of solution

hence for, 50 ml (0.05L), 0.150M HCl solution, we can calculate the total moles of solute by using above formula

0.150 = moles of solute / 0.05

hence after rearranging the equation;

moles of solute = 0.150 x 0.05

Hence. moles of solute = 0.0075 moles

Now, after addition of 30 ml water, total volume will be 80 ml (0.08L),

By using above formula,

Molarity = moles of solute / liters of solution

Molarity = 0.0075 / 0.08

Molarity of solution = 0.093 M