Question

К 140 г 5%-ного раствора поваренной соли добавили 60 г воды. Какова массовая доля соли в полученном растворе? Сколько молекул поваренной соли содержится в полученном растворе?

Answer 1

Ответ:

3.5%NaCl

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Answer 2

Calculation of Mass Fraction of Salt in the Solution

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

Given: - Initial mass of the 5% salt solution = 140 g - Mass of water added = 60 g

To find the mass of salt in the solution, we can subtract the mass of water added from the initial mass of the solution:

Mass of salt in the solution = Initial mass of the solution - Mass of water added

Mass of salt in the solution = 140 g - 60 g = 80 g

The mass fraction of salt in the solution can be calculated by dividing the mass of salt by the total mass of the solution:

Mass fraction of salt = (Mass of salt in the solution / Total mass of the solution) * 100%

Mass fraction of salt = (80 g / 200 g) * 100% = 40%

Therefore, the mass fraction of salt in the obtained solution is 40%.