<PRE><B>Question 230402</B>
A chemist wants to mix distilled water with a 75% solution of sulfuric acid to produce a 60% solution.
 If 3 gallons of distilled water is used, how much of 75% is needed?
:
let x = amt of 75% solution (use the decimal equiv)
:
A simple &quot;amt of acid&quot; equation
.75x = .60(x+3)
.75x = .6x + 1.8
.75x - .6x = 1.8
.15x = 1.8
x = {{{1.8/.15}}}
x = 12 gal of 75% solution required
:
:
Check to see if equality reigns here
.75(12) = .60(12+ 3)
9 = 9</PRE>