SOLUTION: How many mL of acid must be added to 50mL of a 10% acid solution in order to produce a 20% acid solution?

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Question 633942: How many mL of acid must be added to 50mL of a 10% acid solution in order to produce a 20% acid solution?
Answer by Maths68(1474) About Me  (Show Source):
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Solution A
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Amount = x
Concentration = 100% = 1 (Pure acid)

Solution B
==========
Amount = 50ml
Concentration = 10% = 0.1


Mixture
=======
Amount = (x+50)ml
Concentration = 20% = 0.2


(Amount of Solution A)(Concentration of Solution A)+ (Amount of Solution B)(Concentration of Solution B)=(Amount of Mixture)(Concentration of Mixture)
(x)(1)+(50)(0.1)=(x+50)(0.2)
x+5=0.2x+10
x-0.2x=10-5
0.8x=5
0.8x/0.8=5/0.8
x=6.25


6.25mL of acid must be added to 50mL of a 10% acid solution in order to produce 56.25ml of a 20% acid solution.