Source: Extra Practice

If 500 mL of a 5 M solution is diluted to 1500 mL, what is the molarity of the resulting solution?

Options

Option A

1.5 M

Option B is correct

1.66 M

Option C

2.5 M

Option D

0.5 M

Explanation

Using the dilution formula M1V1 = M2V2: (5 M) × (500 mL) = M2 × (1500 mL). M2 = (5 × 500) / 1500 = 2500 / 1500 = 1.666... M. Option 1.5 M is a rounding error, 2.5 M would occur if volume doubled, and 0.5 M is a calculation error.