2. A chemist has a 25% and a 50% acid solution. How much should be used to form 250 mL of a 35% acid
solution?
A) 80 mL of 50% solutions and 120 mL of 25% solution
B) 150 mL of 50% solution and 50 mL of 25% solution
© 60 ml of 50% solution and 140 mL of 25% solution
D) 50 mL of 50% solution and 150 mL of 25% solution
E) None of the above

x is mL of 25% acid and y is mL of 50% acid

We set up 2 equations:

A) x + y = 250

B) .25 x + .50y = .35 * 250 which equals

B) .25x + .50y = 87.50  Multiplying A) by -.5

A) -.5x -.5y = -125  adding the equations we get

-.25x = -37.50

x = 150 mL

y = 100 mL

Source:  http://www.1728.org/mixture.htm

Step-by-step explanation:

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step-by-step explanation: