# Step-by-Step Solution: Chlorination of Methane ## 1. **Write the Balanced Chemical Equation** The chlorination of methane (\(\ce{CH4}\)) in the presence of sunlight is: \[ \ce{CH4 + Cl2 -> CH3Cl + HCl} \] ## 2. **Calculate Moles of Methane** - Molar mass of methane (\(\ce{CH4}\)): \[ 12.01\,(\text{C}) + 4 \times 1.01\,(\text{H}) \approx 16.04\,\text{g/mol} \] (For calculations, use 16 g/mol for simplicity.) - Given mass of methane: \(16\,\text{g}\) - Moles of methane: \[ \text{Moles of } \ce{CH4} = \frac{16\,\text{g}}{16\,\text{g/mol}} = 1\,\text{mol} \] ## 3. **Find Moles of Chlorine Required** From the balanced equation: - **1 mole** of \(\ce{CH4}\) reacts with **1 mole** of \(\ce{Cl2}\). So, \[ \text{Moles of } \ce{Cl2} \text{ needed} = 1\,\text{mol} \] ## 4. **Calculate Volume of Chlorine Gas at STP** At STP (Standard Temperature and Pressure): - **1 mole of any ideal gas occupies 22.4 L** So, \[ \text{Volume of } \ce{Cl2} = 1\,\text{mol} \times 22.4\,\text{L/mol} = 22.4\,\text{L} \] --- ## **Final Answer** **The volume of chlorine gas required at STP is:** \[ \boxed{22.4\,\text{L}} \] --- **Summary Table:** | Substance | Moles Used | Volume at STP (L) | |-----------|------------|-------------------| | Methane (\(\ce{CH4}\)) | 1 | - | | Chlorine (\(\ce{Cl2}\))| 1 | 22.4 | --- **Image:**  *Chlorination of methane reaction diagram*