SOLUTION: 9L of an alcohol solution was mixed with 3L of pure water to make a 15% alcohol solution. find the percent concentration of the first solution
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-> SOLUTION: 9L of an alcohol solution was mixed with 3L of pure water to make a 15% alcohol solution. find the percent concentration of the first solution
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Question 1114885: 9L of an alcohol solution was mixed with 3L of pure water to make a 15% alcohol solution. find the percent concentration of the first solution Found 2 solutions by addingup, greenestamps:Answer by addingup(3677) (Show Source):
You can put this solution on YOUR website! 9x + 3(1) = 12(0.15)
9x + 3 = 1.8
9x = 1.2
x = 0.1333
The percent concentration of the first solution is 13.33%
The solution by tutor adding up is wrong. He mixed the 9L of alcohol solution with 3L of pure alcohol -- not with 3L of pure water.
The 9L of alcohol solution together with the original 3L of pure water makes 12L of mixture. The mixture is 15% alcohol, so the amount of alcohol is 12(0.15) = 1.8L.
1.8L of alcohol in the 9L of alcohol solution means the percentage concentration of the alcohol solution that was added is (1.8/9)*100 = 20%.
Using the formal algebraic method used by the other tutor, but with the right original equation....
