SOLUTION: a pharmacist needs 500 milligrams of a 20% phenobarbital solution but has only 5% and 25% phenobarbital solutions available. find out how many milligrams of each she should mix to
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Question 995457: a pharmacist needs 500 milligrams of a 20% phenobarbital solution but has only 5% and 25% phenobarbital solutions available. find out how many milligrams of each she should mix to get the desired solution? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! a pharmacist needs 500 milligrams of a 20% phenobarbital solution but has only 5% and 25% phenobarbital solutions available. find out how many milligrams of each she should mix to get the desired solution?
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Equation:
pheno + pheno = pheno
0.05x + 0.25(500-x) = 0.20*500
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5x + 25*500 - 25x = 20*500
-20x = -5*500
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x = 500/4
x = 125 ml (amt of 5% solution needed)
500-x = 375 ml (amt of 25% solution needed)
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Cheers,
Stan H.
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