Question

Нужная помощь с задачей по химии, желательно подробное решение с формулами. Заранее благодарю за помощь. При взаимодействии раствора хлорида кальция массой 75г с избытком раствора нитрата серебра выпало 2,87 г осадка. Определите массовую долю хлорида кальция в растворе.

Answer 1

Ответ:

Смотрите вложение.

Объяснение:

Answer 2

Problem Analysis

To determine the mass fraction of calcium chloride in the solution, we need to calculate the amount of calcium chloride reacted with silver nitrate and compare it to the initial mass of calcium chloride.

Solution

1. Calculate the molar mass of calcium chloride (CaCl2) and silver nitrate (AgNO3): - The molar mass of CaCl2 is 40.08 g/mol (1 atom of calcium with a molar mass of 40.08 g/mol and 2 atoms of chlorine with a molar mass of 35.45 g/mol each). - The molar mass of AgNO3 is 169.87 g/mol (1 atom of silver with a molar mass of 107.87 g/mol, 1 atom of nitrogen with a molar mass of 14.01 g/mol, and 3 atoms of oxygen with a molar mass of 16.00 g/mol each).

2. Calculate the number of moles of silver nitrate used: - The mass of the precipitate (silver chloride) formed is 2.87 g. - The molar mass of silver chloride (AgCl) is 143.32 g/mol (1 atom of silver with a molar mass of 107.87 g/mol and 1 atom of chlorine with a molar mass of 35.45 g/mol). - The number of moles of silver chloride formed can be calculated using the formula: moles = mass / molar mass. - Therefore, the number of moles of silver chloride formed is 2.87 g / 143.32 g/mol = 0.02 mol.

3. Calculate the number of moles of calcium chloride reacted: - From the balanced chemical equation, we know that 1 mole of calcium chloride reacts with 2 moles of silver nitrate to form 2 moles of silver chloride. - Therefore, the number of moles of calcium chloride reacted is half the number of moles of silver chloride formed, which is 0.02 mol / 2 = 0.01 mol.

4. Calculate the mass of calcium chloride reacted: - The mass of calcium chloride reacted can be calculated using the formula: mass = moles * molar mass. - Therefore, the mass of calcium chloride reacted is 0.01 mol * 40.08 g/mol = 0.4008 g.

5. Calculate the mass fraction of calcium chloride in the solution: - The initial mass of calcium chloride in the solution is 75 g. - The mass fraction of calcium chloride can be calculated using the formula: mass fraction = (mass of calcium chloride reacted / initial mass of calcium chloride) * 100%. - Therefore, the mass fraction of calcium chloride in the solution is (0.4008 g / 75 g) * 100% = 0.5344%.

Answer

The mass fraction of calcium chloride in the solution is approximately 0.5344%.

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