Question

К 300 граммам 81%-ного раствора ортофосфорной кислоты добавили 150 граммов воды. Рассчитай массовую долю растворённого вещества в образовавшемся растворе.

Answer 1

300*0,81=243 г составляет масса ортофосфорной кислоты в растворе
W(H3PO4)=243/300+150=0,54*100%=54%

Answer 2

Calculation of Mass Fraction of Dissolved Substance

To calculate the mass fraction of the dissolved substance in the resulting solution, we need to consider the initial mass of the 81% orthophosphoric acid solution and the mass of water added.

Given: - Initial mass of the 81% orthophosphoric acid solution: 300 grams - Mass of water added: 150 grams

To calculate the mass fraction of the dissolved substance, we need to determine the mass of the dissolved substance and the total mass of the resulting solution.

1. Calculate the mass of the dissolved substance: - The initial mass of the 81% orthophosphoric acid solution is 300 grams. - Since the solution is 81% orthophosphoric acid, the mass of the dissolved substance is 81% of 300 grams. - Mass of the dissolved substance = 0.81 * 300 grams.

2. Calculate the total mass of the resulting solution: - The total mass of the resulting solution is the sum of the initial mass of the solution and the mass of water added. - Total mass of the resulting solution = Initial mass of the solution + Mass of water added.

3. Calculate the mass fraction of the dissolved substance: - Mass fraction of the dissolved substance = (Mass of the dissolved substance / Total mass of the resulting solution) * 100%.

Let's perform the calculations:

1. Calculate the mass of the dissolved substance: - Mass of the dissolved substance =