SOLUTION: a nurse wishes to add water to 30 ounces of a 10% solution of benzalkonium chloride to dilute it to a 4% solution. How much water must she add?
Question 351742: a nurse wishes to add water to 30 ounces of a 10% solution of benzalkonium chloride to dilute it to a 4% solution. How much water must she add? Answer by ewatrrr(24785) (Show Source):
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*Note: .10*30oz tells us how much benzalkonium chloride is in that total solution
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.10*30oz = 3oz (there are 3 oz of benzalkonium chloride in that total solution)
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Question speaks of making a new 4% solution
Let x be the amount of that "total" solution
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.04*x = 3oz (the actual amount of benzalkonium chloride stays the same)
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x = 3oz/.04 = 75oz
As we already have 30z of "total" solution, 45oz of water will need to be added
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check your answer
.04*75oz = the 3 oz of benzalkonium chloride in the "new total" solution