Question 333345
A chemist has 35% NaCl solution and 50% NaCl solution. How many liters of each should he mix to get 10L of NaCl solution with 40% base concentration?
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Equations:
Quantity: x + y = 10L
Quality: 0.35x + 0.50y = 0.40*10
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Multiply thru 1st by 25
Multiply thru 2nd by 100
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Quantity: 35x + 35y = 35*10
Quality:  35x + 50y = 40*10
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Subtract Quantity from Quality to get:
15y = 5*10
y = 3 1/3 L (amt of 50% NaCl needed in the mixture)
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Solve for "x":
x = 10- 3 1/3 = 6 2/3 L (amt of 35% NaCl needed in the mixture)
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Cheers,
Stan H.