If 4.12 L of 0.850 M H3PO4 is diluted to a final volume of 10.00 L, what is the resulting concentration?

1. Dilution leaves the moles of acid unchanged, so C1V1 = C2V2. 2. Solve for the new concentration: C2 = 0.850 M x 4.12 L / 10.00 L. 3. The result is 0.350 M. 4. Sanity check: the volume grew by roughly 2.4 times, so the concentration must fall by the same factor. 5. The value 2.06 M puts the volumes in upside down, making the diluted acid stronger than the stock. _Source: OpenStax Chemistry (CC BY 4.0), Ch 3 "Composition of Substances and Solutions", section 3.3 Molarity_