Question

Какова массовая доля сахара в растворе, полученом при упаривании 200г 20%-го раствора до 70г? ответ округлить до десятых

Answer 1

При упаривании раствора до 70г, получится концентрация сахара 57,1%

Answer 2

Calculation of the Mass Fraction of Sugar in the Solution

To calculate the mass fraction of sugar in the solution obtained by evaporating 200g of a 20% sugar solution to 70g, we can use the formula:

Mass of Sugar / Mass of Solution = Mass Fraction of Sugar

Let's calculate it step by step:

1. Calculate the initial mass of sugar in the 200g 20% sugar solution: - Mass of sugar = 20% of 200g = 0.2 * 200g = 40g

2. Calculate the final mass of the solution after evaporation: - Mass of solution after evaporation = 200g - 70g = 130g

3. Calculate the mass fraction of sugar in the solution: - Mass fraction of sugar = Mass of sugar / Mass of solution after evaporation - Mass fraction of sugar = 40g / 130g ≈ 0.3077

Therefore, the mass fraction of sugar in the solution obtained by evaporating 200g of a 20% sugar solution to 70g is approximately 0.3077.