Question

1.Смесь оксида кальция и диоксида кремния общей массой 8г обработали избытком соляной кислоты. после фильтрования и выпаривания полученного раствора выделили 11,1г соли. Определите массу каждого оксида в исходной смеси.2.Какая масса оксида кальция необходима для получения карбида кальция массой 32 грамм. Какая масса оксида углерода выделится при этом?

Answer 1

Уравнения реакций:

CaO + 2HCl = CaCl2 + H2O

HCl + SiO2 =/= 

Рассчитаем количество вещества хлорида кальция:

n = m/M = 11,1г/111г/моль = 0,1моль

По уравнению реакции:
n(CaO) = n(CaCl2) = 0.1моль

Рассчитаем массу оксида кальция:

m = n*M = 56г/моль*0,1моль = 5,6г

Рассчитаем w(CaO):

w = m(CaO)/m(см)*100% = 5,6г/8г*100% = 70%

w(SiO2) = 100% - 70% = 30%

 

Answer 2

Task 1: Determining the Mass of Each Oxide in the Mixture

To determine the mass of each oxide in the mixture, we need to use the given information about the total mass of the mixture and the mass of the resulting salt after treatment with excess hydrochloric acid.

Let's assume the mass of calcium oxide (CaO) in the mixture is x grams, and the mass of silicon dioxide (SiO2) is y grams.

According to the law of conservation of mass, the total mass of the mixture is the sum of the masses of the individual components:

x + y = 8 grams ---(Equation 1)

After treating the mixture with excess hydrochloric acid, the resulting solution is filtered and evaporated to obtain 11.1 grams of salt. This salt is a compound of calcium and chlorine, which is likely calcium chloride (CaCl2).

The molar mass of calcium chloride is 110.98 g/mol. To calculate the mass of calcium chloride, we can use the following equation:

Mass of calcium chloride = (11.1 g) / (110.98 g/mol) = 0.0999 mol

Since calcium chloride is formed from calcium oxide and hydrochloric acid, the molar ratio between calcium chloride and calcium oxide is 1:1. Therefore, the number of moles of calcium oxide in the mixture is also 0.0999 mol.

The molar mass of calcium oxide is 56.08 g/mol. To calculate the mass of calcium oxide, we can use the following equation:

Mass of calcium oxide = (0.0999 mol) * (56.08 g/mol) = 5.60 grams

Similarly, the molar ratio between calcium chloride and silicon dioxide is 1:1. Therefore, the number of moles of silicon dioxide in the mixture is also 0.0999 mol.

The molar mass of silicon dioxide is 60.08 g/mol. To calculate the mass of silicon dioxide, we can use the following equation:

Mass of silicon dioxide = (0.0999 mol) * (60.08 g/mol) = 5.99 grams

Therefore, the mass of calcium oxide in the mixture is approximately 5.60 grams, and the mass of silicon dioxide is approximately 5.99 grams.

Task 2: Determining the Mass of Calcium Oxide and Carbon Dioxide in the Formation of Calcium Carbide

To determine the mass of calcium oxide (CaO) required to produce calcium carbide (CaC2) and the mass of carbon dioxide (CO2) released in the process, we need to use the given information about the mass of calcium carbide produced.

The balanced chemical equation for the reaction between calcium oxide and carbon to form calcium carbide is as follows:

CaO + 3C → CaC2 + CO2

From the equation, we can see that the molar ratio between calcium oxide and calcium carbide is 1:1. Therefore, the number of moles of calcium oxide required to produce calcium carbide is the same as the number of moles of calcium carbide produced.

The molar mass of calcium carbide is 64.10 g/mol. To calculate the mass of calcium carbide, we can use the following equation:

Mass of calcium carbide = (32 g) / (64.10 g/mol) = 0.499 mol

Since the molar ratio between calcium oxide and calcium carbide is 1:1, the number of moles of calcium oxide required is also 0.499 mol.

The molar mass of calcium oxide is 56.08 g/mol. To calculate the mass of calcium oxide, we can use the following equation:

Mass of calcium oxide = (0.499 mol) * (56.08 g/mol) = 27.95 grams

Therefore, the mass of calcium oxide required to produce 32 grams of calcium carbide is approximately 27.95 grams.

From the balanced chemical equation, we can see that the molar ratio between calcium oxide and carbon dioxide is 1:1. Therefore, the number of moles of carbon dioxide released in the process is also 0.499 mol.

The molar mass of carbon dioxide is 44.01 g/mol. To calculate the mass of carbon dioxide, we can use the following equation:

Mass of carbon dioxide = (0.499 mol) * (44.01 g/mol) = 21.93 grams

Therefore, the mass of carbon dioxide released in the process is approximately 21.93 grams.

Please note that these calculations are based on the given information and assumptions made about the compounds involved.