Question

При разложении карбоната кальция образуется углекислый газ и негашёная известь.Какая масса карбоната кальция, содержащей 4%примесей,необходима для получения 112г негашенной извести? Помогите пожалуйста с решением этой задачи!!!Очень нужно подробное решение этой задачи.

Answer 1

To solve this problem, we need to determine the mass of calcium carbonate required to produce 112g of unslaked lime (calcium oxide). We are given that the calcium carbonate contains 4% impurities.

Let's break down the steps to solve this problem:

Step 1: Calculate the mass of pure calcium oxide

We are given that the mass of unslaked lime (calcium oxide) is 112g.

Step 2: Calculate the molar mass of calcium oxide

The molar mass of calcium oxide (CaO) is the sum of the atomic masses of calcium (Ca) and oxygen (O). According to the periodic table, the atomic masses of calcium and oxygen are approximately 40.08 g/mol and 16.00 g/mol, respectively.

So, the molar mass of calcium oxide is: Molar mass of CaO = (1 * molar mass of Ca) + (1 * molar mass of O) = (1 * 40.08 g/mol) + (1 * 16.00 g/mol) = 56.08 g/mol

Step 3: Calculate the number of moles of calcium oxide

To find the number of moles of calcium oxide, we can use the formula: Number of moles = Mass / Molar mass

Substituting the given mass of calcium oxide into the formula: Number of moles of CaO = 112g / 56.08 g/mol = 2 moles

Step 4: Calculate the number of moles of calcium carbonate

Since calcium carbonate (CaCO3) decomposes into calcium oxide (CaO), we can use the balanced chemical equation to determine the ratio of moles between calcium carbonate and calcium oxide.

The balanced chemical equation for the decomposition of calcium carbonate is: CaCO3 -> CaO + CO2

From the equation, we can see that 1 mole of calcium carbonate produces 1 mole of calcium oxide.

Therefore, the number of moles of calcium carbonate is also 2 moles.

Step 5: Calculate the mass of pure calcium carbonate

To calculate the mass of pure calcium carbonate, we need to consider the impurities. We are given that the calcium carbonate contains 4% impurities.

Since the impurities make up 4% of the total mass, the pure calcium carbonate makes up 96% of the total mass.

Let's denote the mass of pure calcium carbonate as "x" grams.

The equation to calculate the mass of pure calcium carbonate is: x = (96/100) * total mass of calcium carbonate

Substituting the values: x = (96/100) * (2 moles * molar mass of CaCO3)

Step 6: Calculate the mass of calcium carbonate with impurities

To calculate the mass of calcium carbonate with impurities, we need to consider the percentage of impurities.

Let's denote the mass of calcium carbonate with impurities as "y" grams.

The equation to calculate the mass of calcium carbonate with impurities is: y = x + (4/100) * x

Substituting the value of x: y = [(96/100) * (2 moles * molar mass of CaCO3)] + [(4/100) * (96/100) * (2 moles * molar mass of CaCO3)]

Step 7: Calculate the mass of calcium carbonate

Finally, we can substitute the given values and calculate the mass of calcium carbonate.

Substituting the values into the equation: y = [(96/100) * (2 * 100.09 g/mol)] + [(4/100) * (96/100) * (2 * 100.09 g/mol)]

Simplifying the equation: y = (1.92 * 100.09 g/mol) + (0.0384 * 100.09 g/mol)

Calculating the values: y = 192.19 g + 3.84 g = 196.03 g

Therefore, the mass of calcium carbonate required to produce 112g of unslaked lime (calcium oxide) is approximately 196.03 grams.

Please note that the calculations provided are based on the information given in the question.