<PRE><B>Question 177699</B>
A Laboratory has 60 mL of a solution that is 40% HCl acid. How many mL of 15% HCL acid solution should be mixed with the 60 mL of 40% acid to obtain a solution of 25% HCl
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Active ingredient Equation:
0.40*60 + 0.15x = 0.25(x+60)
Multiply thru by 100 to get:
40*60 + 15x = 25x + 25*60
10 x = 15*60
x = 90 mL (amt. of 15% solution that must be added to the mixture)
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Cheers,
Stan H.</PRE>