<PRE><B>Question 1002191</B>
A chemist needs 1000 mL of a solution that is 40% acid. He has one solution that is 10% acid, and a second solution that is 60% acid. How much of each solution should be mixed together? 
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Equation:
acid + acid = acid
0.10x + 0.60(1000-x) = 0.40*1000
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10x + 60*1000 - 60x = 40*1000
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-50x = -10*1000
x = (1/5)(1000)
x = 200 ml (amt. of 10% solution needed)
1000-x = 800 ml (amt. of 40% solution needed)
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Cheers,
Stan H.
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