How many milliliters of each solution must be mixed to make 50mL of a 9% vinegar solution?

Question

White vinegar is a solution of acetic acid in water. There are two strengths of white vinegar- a 5% solution and a 10% solution. How many milliliters of each solution must be mixed to make 50mL of a 9% vinegar solution?

Answer 1

When the problem informs you that it is a 5% solution, it means that if we divide the container into 100 parts, 5 are acetic acid, and the rest (95!) is water. 

A 10% solution means the same, just 10 parts out of 100 instead of 5.

 

We need to divide the 50 ml into 100 parts, so we can figure out how much acetic acid is in each mixture.

 

50 ml/50 = 1 ml, but that is not enough.

If we divide 50 ml by 100, w get 1/2 ml. (.5 ml).

 

For the 5 percent mixture, that means 5 of these 1/2 ml parts are acetic acid. .5*5= 2.5

2.5/50 ml are actic acid.

 

Since 10% is double 5%, we can double our answer to see how many ml of acetic acid are in the 105 solution.

2.5*2 is 5.5

5 ml out of 50 ml is acetic acid int eh 10% solution.