Question

25) A chemist has 10 L of a solution that is 10% nitric acid by volume. He wants to dilute the
solution to 40% strength by adding water. How many litres of water must be added?
(a) 15L
(b) 20L
(c) 18 L
(d) 25L
(e) None of these​

Answer 1

Answer:

Total= 10 lt

Acid= 1

Water= 9

Water to add= x

1/(10+x) = 4/100

so x is 15.