Question

Ella has 0.5 lbs of sugar. How much water should she add to make the following concentrations? Tell Ella how much syrup she will have in each case. 20%, 25% and 1.5% syrup?

Answer 1

Concentration = [ (mass of sugar)/(mass of solution) ] * 100

=> mass of solution = mass of sugar * 100 / concentration

1) concentration 20%

mass of sugar = 0.5 lbs

=> mass of solution = mass of sugar * 100 / concentration = 0.5 lbs * 100 / 20

mass of solution = 2,5 lbs

mass of water = mass of solution - mass of sugar = 2.5 lbs - 0.5 lbs = 2.0 lbs

Answer: she must add 2.0 lbs of water and will obtain 2.5 lbs of syrup

2) concentration 25%

Follow the same procedure.

mass of solution = 0.5 lbs * 100 / 25 =

mass of solution = 2.0 lbs

mass of water = 2.0 lbs - 0.5 lbs = 1.5lbs

Answer: she has to add 1.5 lbs of water and will obtain 2.0 lbs of syrup

3) Same procedure

mass of solution = mass of sugar * 100 / concentration = 0.5 lbs * 100 / 1.5

mass of solution = 33.33 lbs

mass of water = 33.33 lbs - 0.5 lbs = 32.83 lbs

Answer: she has to add 32.83 lbs of water and will obtain 32.83 lbs of syrup