Question

Помогите пожалуйста решить задачу.Из 200 грамм 30 % раствора соли выпарили 75 грамм воды, а затем добавили 25 грамм соли. Вычислите массовую долю соли в новом растворе

Answer 1

1) 200 * 30 : 100 = 60 г - масса соли в 30 %-ном растворе
2) 60 + 25 = 85 г - масса соли в новом растворе
3) 200 - 75 + 25 = 150 г - масса нового раствора
4) 85 : 150 * 100 % = 56,67 % - массовая доля соли в новом растворе

Answer 2

Task:

Вычислите массовую долю соли в новом растворе, если из 200 грамм 30% раствора соли выпарили 75 грамм воды, а затем добавили 25 грамм соли.

Solution:

To solve this problem, we need to calculate the mass fraction of salt in the new solution.

Let's break down the problem step by step:

1. Initially, we have a 30% salt solution with a mass of 200 grams. This means that 30% of the solution's mass is salt, and the remaining 70% is water. - The mass of salt in the initial solution is 30% of 200 grams, which is 60 grams. - The mass of water in the initial solution is 70% of 200 grams, which is 140 grams.

2. Next, we evaporate 75 grams of water from the solution. This means that the mass of water in the solution is reduced by 75 grams, while the mass of salt remains the same. - After evaporation, the mass of water in the solution is 140 grams - 75 grams = 65 grams. - The mass of salt in the solution remains 60 grams.

3. Finally, we add 25 grams of salt to the solution. - The total mass of salt in the new solution is 60 grams + 25 grams = 85 grams. - The total mass of the solution is 65 grams (water) + 85 grams (salt) = 150 grams.

To calculate the mass fraction of salt in the new solution, we divide the mass of salt by the total mass of the solution and multiply by 100%: - Mass fraction of salt = (mass of salt / total mass of solution) * 100%

Let's calculate the mass fraction of salt in the new solution:

- Mass fraction of salt = (85 grams / 150 grams) * 100% = 56.67%

Therefore, the mass fraction of salt in the new solution is approximately 56.67%.

Please let me know if you need any further assistance!