document.write( "Question 295910: 1. A chemical engineer mixed 40ml of 8% hydrochloric acid with 60ml of 12% hydrochloric acid solution. He used a portion of this solution and replaced it with distilled water. If the new solution tested 5.2% hydrochloric acid, how much of the original mixture did he use.\r
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Algebra.Com's Answer #213310 by nerdybill(7384)\"\" \"About 
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1. A chemical engineer mixed 40ml of 8% hydrochloric acid with 60ml of 12% hydrochloric acid solution. He used a portion of this solution and replaced it with distilled water. If the new solution tested 5.2% hydrochloric acid, how much of the original mixture did he use.
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\n" ); document.write( "From:A chemical engineer mixed 40ml of 8% hydrochloric acid with 60ml of 12% hydrochloric acid solution.
\n" ); document.write( "amount of acid = .08(40) + .12(60)
\n" ); document.write( "amount of acid = 3.2 + 7.2
\n" ); document.write( "amount of acid = 10.4 ml
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\n" ); document.write( "total amount of solution = 40+60 = 100 ml
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\n" ); document.write( "concentration of solution = 10.4/100 = .104
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\n" ); document.write( "Let x = amount of solution used and replaced with distilled water
\n" ); document.write( "then
\n" ); document.write( ".104(100-x) = .052(100+x)
\n" ); document.write( "10.4 - .104x = 5.2 + .052x
\n" ); document.write( "10.4 = 5.2 + .156x
\n" ); document.write( "5.2 = .156x
\n" ); document.write( "33.33 ml = x\r
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