contestada

A scientist needs 180 milliliters of a 20% acid solution for an experiment. The lab has available a 25% and a 10% solution. How many milliliters of the 25% solution and how many milliliters of the 10% solution should the scientist mix to make the 20% solution

Respuesta :

sqdancefan

9514 1404 393

Answer:

  • 120 mL of 25% solution
  • 60 mL of 10% solution

Step-by-step explanation:

Let q represent the quantity of 25% solution in the mix. Then 180-q is the quantity of 10% solution. The quantity of acid in the mix is ...

  0.10(180 -q) +0.25(q) = 0.20(180)

  18 +0.15q = 36 . . . . simplify

  0.15q = 18 . . . . . . . . subtract 18

  q = 18/0.15 = 120 . . . . divide by the coefficient of q

  180-q = 60

The scientist should mix 120 mL of 25% solution with 60 mL of 10% solution.

Otras preguntas