0.1 mol of NaCl is dissolved to make 0.25 L of solution. What is the molarity?

A) 0.8 M

B) 0.4 M

C) 0.2 M

D) 0.5 M

Answer: B

Explanation: Molarity equals moles of solute divided by final solution volume in liters. 0.1 mol divided by 0.25 L gives 0.4 mol/L.