Question

What volume of 8.50 M H3PO4 is required to prepare 204 mL of a 0.750 M solution?

Answer 1

Solution:

In order to get the answer, you have to use the dilution equation:

C_M1 × V₁ = C_M2 × V₂

where:

C_M1 is the initial concentration (8.50 M)

V₁ is the initial volume (unknown)

C_M2 is the final concentration (0.750 M)

V₂ is the final volume (204 mL)

We know C_M1, C_M2, and V₂.

Thus:

V₁ = C_M2 × V₂ / C_M1

V₁ = (0.750 M × 204 mL) / 8.50 M = 18 mL

V₁ = 18 mL.

Answer: 18 mL of H₃PO₄.