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Question 190078: Could you PLEASE help me with this problem?: Determine the mL of water needed to prepare 2oz of a 10% solution from a 12.5% solution and distilled water.
I would really appreciate it! thnx!
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! Could you PLEASE help me with this problem?: Determine the mL of water needed to prepare 2oz of a 10% solution from a 12.5% solution and distilled water.
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The solution is to be 10% something and 90% water. Let's call the something "s" to save typing.
2 oz of 10% s means there's 0.2 oz of s in the mixture. See that? The other 1.8 oz is water.
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To get 0.2 oz from the 12.5% mix will take 1.6 oz. (12.5% is 1/8, so 1.6 times 1/8 = 0,2 oz). Am I going too fast for you? Take your time, think about it. The important thing is NOT to get the answer, but to understand how to get it.
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The 1.6 oz has the 0.2 oz of s, so you add the difference in water, 0.4 ounces.
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To sum it up, you mix 1.6 oz of the 12.5% mix with 0.4 oz of water. The result is 2 ounces of 10% mix.
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PS I really, really hope I got this one right.
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