Answer:
16 liters of the solution with 40% concentration must be mixed with 62 liters of the solution with 25% concentration in order to obtain 78 liters, 25% concentration solution.
Explanation:
Let the required volume of solution 1 be represented by x.
The required volume of solution 2 would then be 78-x.
The number of moles of solution 1 that would be required = 0.4x
The number of moles of solution 2 that would be required = 0.25(78-x)
The number of moles of the final mixture = 78 x 0.28 = 21.84
moles of solution 1 + moles of solution 2 = moles of final mixture
0.4x + 0.25(78 - x) = 21.84
0.4x + 19.5 - 0.25x = 21.84
0.4x - 0.25x = 21.84 - 19.5
0.15x = 2.34
x = 15.6 liters
To the nearest tenth = 16 liters
<em>Liters of 40% solution needed = 16 liters</em>
<em>Liters of 25% solution needed = 78 - 16 = 62 liters.</em>
<u>Hence, 16 liters of the solution with 40% concentration must be mixed with 62 liters of the solution with 25% concentration in order to obtain 78 liters, 25% concentration solution. </u>
