Question

A 9 L solution that was 11% vinegar was mixed with a 10 L solution that was 69%vinegar.find the new concentration of vinegar

Answer 1

1st solution: 9L 11% Vinegar, 9, 11
2nd solution: 10L 69% Vinegar 10, 69
Total volume when mixed = 9 + 10 = 19

Using, law of mixtures:

Volume1 * Concentration 1 + Volume2 * Concentration2 = Total Volume * Final Concentration
Volume is in L, and Concentration is in %

9*11 + 10*69 = 19* FC, Where FC = Final Concentration
99 + 690 = 19FC
789 = 19FC Divide both sides by 19

789/19 = FC
41.52 = FC

Therefore final concentration after mixing = 41.52%