<PRE><B>Question 637225</B>
She need o prepare 12 liters of a 9% hydrochloric solution. Find the amount of a 4% solution and the amount of a 12% solution she should mix to get this solution.
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Equation:
acid + acid = acid
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0.04x + 0.12(12-x) = 0.09*12
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Multiply thru by 100 to get:
4x + 12*12 - 12x = 9*12
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-8x = -3*12
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x = 3(3/2) = 4.5 liters (amt. of 4% solution needed)
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12-x = 7.5 liters (amt. of 12% solution needed)
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Cheers,
Stan H.
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