Question

К 300 г 2% раствора добавили 40 г соли.Найти массовую долю соли в р-ре?

Answer 1

Определим массу соли в исходном р-ре m= 300*0,02=6г. Тогда массовая доля в новом р-ре будет равна 6/(300+40)=0,0176 или 1,76%

Answer 2

Calculation of Mass Fraction of Salt in the Solution

To find the mass fraction of salt in the solution, we need to calculate the total mass of the solution and the mass of the salt added.

Given: - Initial solution mass (m1) = 300 g - Concentration of the initial solution (c1) = 2% - Mass of salt added (m2) = 40 g

To calculate the mass fraction of salt, we can use the formula:

Mass Fraction of Salt (w) = (Mass of Salt / Total Mass of Solution) * 100%

Let's calculate the total mass of the solution first.

Total Mass of Solution = Initial solution mass + Mass of salt added Total Mass of Solution = 300 g + 40 g Total Mass of Solution = 340 g

Now, we can calculate the mass fraction of salt.

Mass Fraction of Salt (w) = (40 g / 340 g) * 100%

Calculating the above expression, we find:

Mass Fraction of Salt (w) ≈ 11.76%

Therefore, the mass fraction of salt in the solution is approximately 11.76%.