Question

К 200г р-ра хлорида кальция добавили р-р карбоната натрия до прекращения выпадения осадка.Масса осадка составила 12 г.Рассчитать массовую долю хлорида кальция в исходном растворе помогите пожалуйста, желательно с фото

Answer 1

Решение задачи. Ответ 6,66%

Answer 2

Решение на картинке:

Answer 3

Calculation of the Mass Fraction of Calcium Chloride in the Initial Solution

To calculate the mass fraction of calcium chloride in the initial solution, we need to use the information provided. According to the question, 200 grams of a calcium chloride solution was mixed with a sodium carbonate solution until precipitation ceased. The mass of the precipitate obtained was 12 grams.

To find the mass fraction of calcium chloride, we can use the following formula:

Mass Fraction = (Mass of Calcium Chloride / Mass of Solution) x 100%

In this case, the mass of the calcium chloride is not given directly. However, we can assume that the mass of the precipitate obtained is solely due to the calcium chloride reacting with the sodium carbonate. Therefore, we can consider the mass of the precipitate as the mass of calcium chloride.

Using the given information, the mass of the calcium chloride is 12 grams, and the mass of the solution is 200 grams. Plugging these values into the formula, we can calculate the mass fraction:

Mass Fraction = (12 grams / 200 grams) x 100%

Calculating this expression, we find that the mass fraction of calcium chloride in the initial solution is 6%.

Please note that the calculation assumes that the reaction between calcium chloride and sodium carbonate goes to completion and that there are no other factors affecting the precipitation of the calcium carbonate.