<PRE><B>Question 776156</B>
an acid solution was made by mixing 1L of a 40% acid solution and 4L of a 70% solution. what is the concentration of the mixture? 
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Equation:
acid + acid = acid
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1*0.40 +4*0.70 = x*(1+4)
Multiply thru by 100 to get rid of the decimals:
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40 + 70*4 = 500x
320 = 500x
x = 0.64 = 64%
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Cheers,
Stan H.
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