Question 633939

Solution A
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Amount = 10ml 
Concentration =30% =0.3 

Solution B
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Amount = 30ml
Concentration =50% = 0.5

Mixture
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Amount =10+30 = 40ml 
Concentration =x

[Amount Solution A * Concentration A] + [Amount Solution B * Concentration of B]  =[Amount of Mixture *Concentration of Mixture]

(10)(0.3)+(30)(0.5)=(40)(x)
3+15=40x
18=40x
x=18/40
x=0.45
x=45/100=45%

A chemist mixes 10L of a solution that is 30% acid with 30L of a solution that is 50% acid to prepare 40ml mixture that is 45% acid.