Question

.How many gallons of hydrochloric acid must be added to

12 gallons of a 30% solution to obtain a 40% solution

Answer 1

5.6

Explanation:

.30*12+x=.40(12+x)

3.6+x=4.8+.40x

x-.40x=4.8-3.6

.6x=1.2

x=1.2/.6

x=2 gallons of acid needs to be added.

Proof:

.30*12+2=.4(12+2)

3.6+2=.4*14

5.6=5.6