You need a 40% alcohol solution. On hand, you have a 100 mL of a 25% alcohol mixture. You also have 65% alcohol mixture. How much of the 65% mixture will you need to add to obtain the desired solution

60 ml of the 65% mixture will you need to add to obtain the desired solution.

Explanation:

According to the dilution law,

where,

= concentration of given alcohol solution = 25 %

= volume of given alcohol solution = 100 ml

= concentration of another alcohol solution=65 %

= volume of another acid solution= x ml

 = concentration of resulting alcohol solution = 40 %

= volume of resulting acid solution = (100+x)

Thus 60 ml of the 65% mixture will you need to add to obtain the desired solution.