50 g of sugar solution with a mass fraction of dissolved substance 10% evaporated 30 g.

50 g of sugar solution with a mass fraction of dissolved substance 10% evaporated 30 g. Find the mass fraction of sugar in the solution after evaporation.

Let’s use the following formula:

mr.v. = (mr-ra * wr.v.) / 100%

mr.v. = (50 gr * 10%) / 100% = 5 gr.

30 grams of water was evaporated from the solution, which means the mass of the resulting solution is:

mr-ra = 50 gr – 30 gr = 20 gr.

Let’s use the following formula to find the mass fraction of sugar after evaporation of the solution:

wr.v. = (mr.w. * 100%) / mr-ra

wr.v. = (5 gr * 100%) / 20 gr = 25%

Answer: 25%.