<PRE><B>Question 102385</B>
how much pure acid should be mixed with 7 gallons of a 40% acid solution in order to get a 70% acid solution?
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Comment: Follow the acid.
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40% solution DATA:
Amt = 7 gallons ; amt of acid = 0.07*7 = 0.49 gallons
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100% solution DATA;
Amt = x gallos ; amt of acid = x gallons
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70% mixture DATA:
amt = x+7 gallons ; amt of acid = 0.70(x+7)= (0.70x + 4.9) gallons
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EQUATION:
acid + acid = acid
0.49 + x = 0.70x + 4.9
0.30x = 4.41
x = 14.7 gallons (amt of 100% solution that must be added)
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Cheers,
Stan H.

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