Question

Which equation should you use to find the final concentration?

mc001-1.jpg

mc001-2.jpg

mc001-3.jpg

Answer 1

I can’t see the images you attached — could you either re-upload them or paste the text of the problem and the three equation choices?

Meanwhile, here are the usual equations and when to use each so you can check which fits your problem:

- C1V1 = C2V2 (or M1V1 = M2V2)
- Use when you dilute a single stock solution to a new volume (you only add solvent to one solution).

- Cfinal = (C1V1 + C2V2 + …) / (V1 + V2 + …)
- Use when you mix two or more solutions of known concentrations and volumes to get a final concentration.

- n = C·V (and Cfinal = ntotal / Vtotal)
- Use when you compute moles from concentration and volume for one or more species, then divide total moles by total volume.

- MaVa = MbVb (or equivalents)
- Use for neutralization/titration problems relating equivalents of acid/base.

If you upload the images or tell me the scenario (dilution vs mixing, concentrations given, volumes given), I’ll tell you exactly which equation to use.