Question 627310
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
how much pure acid{{{highlight(x)}}} should be mixed with 5 gallons of a 30% acid solution
in order to get a 50% acid solution?
    acid + acid = acid
 {{{x +  .30*5gal = .50(5+x)}}}
            {{{ .5x = .20*5}}}
                  x = 2 gal

Note:  2gal + 1.5gal = 3.5gal                      
Set Up on ALL mixture problems is to have the same amount of the <u>key ingredient</u> on both sides of the EQ