The percentage composition of carbon by mole in methane is:

Options

A. 0.75
B. 0.8
C. 0.2
D. 25%.

Answer

To find the percentage composition of carbon by mole in methane (CH₄), follow these steps:

### Step 1: Identify the formula of methane
The chemical formula of methane is CH₄, which indicates that it consists of:
- 1 carbon atom (C)
- 4 hydrogen atoms (H)

### Step 2: Calculate the total number of moles
To find the total number of moles in methane, add the moles of carbon and hydrogen:
- Moles of carbon = 1
- Moles of hydrogen = 4

Total moles = Moles of carbon + Moles of hydrogen
Total moles = 1 + 4 = 5 moles

### Step 3: Calculate the percentage of carbon by mole
To find the percentage of carbon by mole, use the formula:
\[ \text{Percentage of Carbon} = \left( \frac{\text{Moles of Carbon}}{\text{Total Moles}} \right) \times 100 \]
Substituting the values:
\[ \text{Percentage of Carbon} = \left( \frac{1}{5} \right) \times 100 = 20\% \]

### Final Answer
The percentage composition of carbon by mole in methane is **20%**.

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