Question 252331: Chemistry: Salt Solution. How much water must be evaporated from 32 ounces of a 4% salt solution to make a 6% salt solution? Found 2 solutions by Alan3354, oberobic:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! How much water must be evaporated from 32 ounces of a 4% salt solution to make a 6% salt solution?
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4% of 32 ounces is 1.28 oz of salt.
for 1.28 oz to be 6%, the total has to be 1.28/0.06 = 21.333...
32 - 21 1/3 = 10 2/3 ounces of water lost
You can put this solution on YOUR website! A key concept is view this type of problem in terms of the amount of 'pure stuff' you need.
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You are told you have 32 oz of a 4% salt solution.
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4%(32) = .04*32 = 1.28 oz of pure salt.
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Given 1.28 oz of pure salt, how much 6% solution would that make?
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Let 'x' be the unknown volume. Solve...
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1.28/x = .06
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Rearranging...
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0.06x = 1.28
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Multiply both sides by 100 to remove the decimals
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6x = 128
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Divide both sides by 6.
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x = 21 1/3 = 21.3333
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So a 21.3333 oz solution containing 1.28 oz of salt will be a 6% solution.
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Looking back at the question, it asks how much must be evaporated.
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32 - 21 1/3 = 10 2/3 = 10.667
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Done.
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