Question

Calculate the molarity of 0.50 mol MgCl2 in 750 ml of solution.

Answer 1

Molarity = mol/L

0.50 mol of MgCl2
0.750 L (1000 mL = 1 L)

Molarity = 0.5 mol/0.75 L = 0.666667 M

Answer 2

Answer : The correct answer for molarity of MgCl₂ solution is 0.67 M.

Molarity :

It expresses concentration of any solution . It can be defined as mole of solute present in volume of solution in Liter .

It uses unit M or $\frac{mol}{L}$

It can be formulated as :

$Molarity (\frac{mol}{L} ) = \frac{mole of solute (mol)}{volume of solution (L)}$

Given : mol of MgCl₂ (solute ) = 0.50 mol

Volume of solution = 750 mL

Following steps can be done :

Step 1 ) To convert volume of solution from mL to L

1 L = 1000 mL

$Volume of solution = 750 mL * \frac{1 L}{1000mL}$

Volume of solution = 0.750 L

Step 2) To find molarity

Plugging mole of solute and volume of solution in molarity formula as :

$Molarity = \frac{0.50 mol}{0.750 L }$

$Molarity = 0.67 \frac{mol}{L}$

Hence molarity of MgCl₂ solution is 0.67 M