Question 403247
let x be the amount of water to add

The final amount of liquid will be (75 + x)

the key thing to realize is that the amount of actual pure acid before adding water is THE SAME as the amount of actual pure acid after adding water - its just that in one case you have less liquid but a stronger solution and in the other case you have more liquid but a weaker solution


since the amount of pure acid is the same we can say that

0.75(75) = 0.45(75 + x)

56.25 = 33.75 + 0.45x

if a = b, then b = a, so

33.75 + 0.45x  = 56.25

0.45x = 22.5

x = 22.5/0.45

x = 50 ml