Question

What is the molarity of a solution made with 400 grams of copper II chloride in 3.5 liters of water?

Answer 1

Answer:

0.85M

Explanation:

Given parameters:

Mass of CuCl₂  = 400g

Volume of water  = 3.5L

Unknown:

Molarity of the solution = ?

Solution:

Molarity is one of the ways of expressing the concentrations of a solution. It is defined as the number of moles per unit volume of a solvent.

          Molarity  = $\frac{number of moles}{volume}$

To find the number of moles of CuCl₂;

    Number of moles  = $\frac{mass}{molar mass}$

  Molar mass of CuCl₂ = 63.6 + 2(35.5)  = 134.6g/mol

   Number of moles  = $\frac{400}{134.6}$   = 2.97moles

      Molarity  = $\frac{2.97}{3.5}$    = 0.85M