Question

What is the molarity of a solution that contains 0.5 mol of NaCl in 250 mL of solution?

• A. 1 M
• B. 2 M
• C. 0.5 M
• D. 0.25 M

Hint:

Always convert volume to liters when calculating molarity: \( 1000 \, \text{mL} = 1 \, \text{L} \). Molarity = Moles / Liters

Answer 1

The Correct Option is B

Molarity (M) is defined as: \[ M = \frac{\text{moles of solute}}{\text{volume of solution in L}} \] Given: Moles of NaCl = 0.5 mol
Volume of solution = 250 mL = 0.25 L \[ M = \frac{0.5}{0.25} = 2 \, \text{mol/L} = 2 \, \text{M} \] Option (b) is correct.