Calculate the weight of lime (CaO) obtained by heating 2000kg of 95% pure lime stone (CaCO3

Answer

To calculate the weight of lime (CaO) obtained by heating 2000 kg of 95% pure limestone (CaCO3), we can follow these steps:

### Step 1: Determine the amount of pure CaCO3 in the limestone sample
Given that the limestone is 95% pure, we can calculate the amount of pure calcium carbonate (CaCO3) in 2000 kg of limestone.

\[ \text{Weight of pure CaCO3} = \text{Total weight of limestone} \times \left(\frac{\text{Purity}}{100}\right) \]

\[ \text{Weight of pure CaCO3} = 2000 \, \text{kg} \times \left(\frac{95}{100}\right) = 1900 \, \text{kg} \]

### Step 2: Use the decomposition reaction of CaCO3
When calcium carbonate (CaCO3) is heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO2) according to the following reaction:

\[ \text{CaCO}_3 \, (s) \rightarrow \text{CaO} \, (s) + \text{CO}_2 \, (g) \]

### Step 3: Calculate the mass of CaO produced from the mass of CaCO3
From the molar masses, we know:
- Molar mass of CaCO3 = 100 g/mol (40 for Ca + 12 for C + 3*16 for O)
- Molar mass of CaO = 56 g/mol (40 for Ca + 16 for O)

From the reaction, 100 g of CaCO3 produces 56 g of CaO. Therefore, we can set up a proportion to find out how much CaO is produced from 1900 kg of CaCO3.

\[ \text{Weight of CaO} = \text{Weight of CaCO3} \times \left(\frac{\text{Molar mass of CaO}}{\text{Molar mass of CaCO3}}\right) \]

\[ \text{Weight of CaO} = 1900 \, \text{kg} \times \left(\frac{56}{100}\right) = 1064 \, \text{kg} \]

### Final Answer
The weight of lime (CaO) obtained by heating 2000 kg of 95% pure limestone is **1064 kg**.

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