How much wat must be evaporated from a 65-gallon tank of 40% salt solution in order to obtain an 80% salt solution?

Answer 1

C1 V1 = C2 V2

0.4 x 65 = 0.8 x V2

V2 = 65/2 = 32.5 gallons

amount that must evaporate = 65-32.5
= 32.5