What will be the volume of` CO_(2)` at NTP obtained on heating 10 grams of (90% pure) limestone?

Options

A. (a)22.4 litres
B. (b)2.016 litres
C. (c )2.24 litres
D. (d)20.16 litres

Explanation

To find the volume of CO₂ produced at NTP from heating 10 grams of 90% pure limestone (calcium carbonate, CaCO₃), we can follow these steps:

### Step 1: Determine the mass of pure calcium carbonate
Since the limestone is 90% pure, we first calculate the mass of pure calcium carbonate in 10 grams of limestone.

\[ \text{Mass of pure CaCO}_3 = 10 \, \text{g} \times \frac{90}{100} = 9 \, \text{g} \]

### Step 2: Calculate the molar mass of calcium carbonate (CaCO₃)
The molar mass of calcium carbonate is calculated as follows:

\[ \text{Molar mass of CaCO}_3 = \text{Atomic mass of Ca} + \text{Atomic mass of C} + 3 \times \text{Atomic mass of O} \]
\[ = 40 \, \text{g/mol} + 12 \, \text{g/mol} + 3 \times 16 \, \text{g/mol} = 100 \, \text{g/mol} \]

### Step 3: Calculate the number of moles of pure CaCO₃
Using the mass of pure CaCO₃, we can find the number of moles:

\[ \text{Number of moles of CaCO}_3 = \frac{\text{Mass of CaCO}_3}{\text{Molar mass of CaCO}_3} = \frac{9 \, \text{g}}{100 \, \text{g/mol}} = 0.09 \, \text{mol} \]

### Step 4: Determine the moles of CO₂ produced
From the thermal decomposition of calcium carbonate, we know that 1 mole of CaCO₃ produces 1 mole of CO₂. Therefore, the moles of CO₂ produced will also be 0.09 mol.

### Step 5: Calculate the volume of CO₂ at NTP
At NTP (Normal Temperature and Pressure), 1 mole of any gas occupies 22.4 liters. Thus, the volume of CO₂ produced can be calculated as follows:

\[ \text{Volume of CO}_2 = \text{Number of moles of CO}_2 \times 22.4 \, \text{L/mol} = 0.09 \, \text{mol} \times 22.4 \, \text{L/mol} = 2.016 \, \text{L} \]

### Final Answer
The volume of CO₂ produced at NTP from heating 10 grams of 90% pure limestone is **2.016 liters**.

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