SOLUTION: how much pure acid should be mix with 2 gallonsof 40% acid solution in order to get a 70%acid solution. can you please show me how to do it my self, thanks

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Question 188875: how much pure acid should be mix with 2 gallonsof 40% acid solution in order to get a 70%acid solution. can you please show me how to do it my self, thanks
Found 2 solutions by Alan3354, nerdybill:
Answer by Alan3354(21608) (Show Source):
You can put this solution on YOUR website!
how much pure acid should be mix with 2 gallonsof 40% acid solution in order to get a 70%acid solution.
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2 gals of 40% has 0.8 gals of acid and 1.2 gals of water.
If acid is added to be 70%, then the 1.2 gals of water will be 30% of the solution.
If 1.2 gals is 0.3 of the solution, then the total is 4 gallons. Add 2 gallons to make it 70%.

Answer by nerdybill(5412) (Show Source):
You can put this solution on YOUR website!
how much pure acid should be mix with 2 gallonsof 40% acid solution in order to get a 70%acid solution. can you please show me how to do it my self, thanks
.
Let x = amount of pure (100%) acid added
then
"amt of acid added" + "amt of acid of original mix" = "70% of total mixture"
x + .40(2) = .70(x+2)
x + .80 = .70x + 1.40
.30x + .80 = 1.40
.30x = .60
x = .60/.30
x = 2 gallons