Answer:
x = amount of pure acid to be added = 6.67ml
Step-by-step explanation:
George wishes to increase the percent of acid in 50ml of a 15% acid solution in water to 25% acid, how much pure acid must you add?
let
x = amount of pure acid to be added
15% of 50 + x = 25% of 50 + x
(0.15 * 50) + x = 0.25(50 + x)
7.5 + x = 12.5 + 0.25x
Collect like terms
x - 0.25x = 12.5 - 7.5
0.75x = 5
x = 5/0.75
x = 6.6666666666666
Approximately,
x = 6.67
x = amount of pure acid to be added = 6.67ml