Question

How many grams of CuF2 are needed to make a 2.8 M solution

Answer 1

Molarity is given as,

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

Also, Moles is given as,

Moles = Mass / M.mass

Substituting value of moles in eq. 1,

Molarity = Mass / M.mass × Volume

Solving for Mass,

Mass = Molarity × M.mass × Volume ---- (2)

Data Given;

Molarity = 2.8 mol.L⁻¹

M.mass = 101.5 g.mol⁻¹

Volume = 1 L (I have assumed it because it is not given)

Putting values in eq. 2,

Mass = 2.8 mol.L⁻¹ × 101.5 g.mol⁻¹ × 1 L

Mass = 284.2 g of CuF₂