Question

Calculate the molarity (M) of 4.62 grams of MgCl2 in 250 mL of solution

A) 2.0 M
B)0.31 M
C)0.194 M
D)0.02 M

Answer 1

Molarity is defined as the moles of solute divided by the liter of solution. In this case the moles of solute can be obtained by dividing 4.62 g of MgCl2 to its MW of 95.211 g/mol. The moles of MgCl2 obtained is then divided by the 0.250 L of the solution. The resulting molarity is then equal to 0.194 M.