A=%b problem

[JERRY GRAHAM]

Problem: A chemist has 5 gallons of sulfuric acid. He needs a solution that is 85% sulfuric acid. How much water does he need to to produce the solution needed?
I just can't remember how to do this.

 

[stapel]

See if the following jogs your memory:

. . . . .various liquid-mixture problems

Eliz.

 

[JERRY GRAHAM]

Thanks for the reply, but visiting the site didn't help. Right now all I can think is that if I have 85% sulfuric acid, I need 15% water. I don't know the formula for telling me how many gallons that is.

 

[soroban]

Hello, Jerry!

A chemist has 5 gallons of sulfuric acid.
He needs a solution that is 85% sulfuric acid.
How much water does he need to to produce the solution needed?

He will add \(\displaystyle x\) gallons of water.

The total solution will contain \(\displaystyle x\,+\,5\) gallons of which 85% is acid.

That is: \(\displaystyle \,85\%\,\text{of}\,x\,+\,5\.\) is the original 5 gallons of acid.

Our equation is: \(\displaystyle \:0.85(x\,+\,5)\:=\:5\)

 

[JERRY GRAHAM]

To Soroban, THANK YOU, THANK YOU!