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Old 02-08-08, 02:02 PM   #828 (permalink)
kcallahan
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Originally Posted by TheFang View Post
This is only an example, so I am not cheating off you.
How do you figure that?
Using one of the books examples:
A chemist needs to mix 20L of a 40% acid solution with some 70% acid solution to obtain a mixture that is 50% acid. How many liters of the 70% acid solution should be used?
did you use the equation:
0.70x + 0.40(20) = 0.50(x+20)
?
Anyhow after working this out you get the answer of 10.
You're sure working my brain on a Friday afternoon. In you first example I just calculated the ratio to be 3:1 to get the 14%.

For the example above I calculated the ratio to be 2:1 Since you had 20L of 40% you'd need 10L of 70%.

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