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#1 2013-01-17 22:13:03


mixture problem

A 90% KCN solution is diluted with water to make a solution of 60% acid. When 3 gallons of water is added to dilute it again, the solution becomes 40% acid.
a. how much water was added to the solution on the first instance?
b. what was the original volume of the 90% acid solution?

#2 2013-01-17 23:00:19

From: Bumpkinland
Registered: 2009-04-12
Posts: 92,921

Re: mixture problem


K = the amount of KCN
w = the amount of water
a = amount of water added

K = 2 / 5

w = 18 / 5

a = 2

You should be able to answer a and b now.

By the way, KCN is the salt of a strong base KOH and a weak acid HCN therefore is it a base not an acid.

In mathematics, you don't understand things. You just get used to them.

I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.


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