How much water must be evaporated from 36 ounces of a 3 % salt solution to make a 9% salt​ solution?

Question

Last one :-)

Answer 1

We have a 36 oz solution, 3% of which is salt.

.03(36) = 1.08 oz of salt

 

We need to find out how much solution will

1.08 oz of salt be 9% of...

 

.09S = 1.08

S = 1.08/.09

S = 12 ounces

 

1.08 ounces of salt is 9% of a 12 ounce solution.

 

If we had 36 ounces, and need to end up with 12 ounces,

we need to evaporate 24 ounces of water