How much pure acid should be mixed with 6 gallons of a 10% acid solution in order to get a 90% acid solution

Question

Does anybody know the answer to my question

Answer 1

Hi Jaraisha!

So we know that we are adding pure acid, so that would be 100%. We do not know how much pure acid we are adding, so we will assign x to represent that quantity. Forming the equation, we get

1.00x + 0.10(6) = 0.90 (x + 6)

Simplifying, we get

x + .6 = 0.9x + 5.4

x − 0.9x = 5.4 − .6

0.1x = 4.8

x = 4.8/0.1 

x = 48

So we need 48 gallons of pure acid.

Answer 2

0.10(6) + 1.00x = 0.90(6 + x)

Can you solve for x and answer?