Gram molecular mass of `CH_4` is

Options

A. 16 g
B. 16 u
C. 32 g
D. 32 u

Answer

To find the gram molecular mass (or molar mass) of methane (CH₄), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Molecular Formula**: The molecular formula of methane is CH₄, which consists of one carbon atom and four hydrogen atoms.

2. **Determine Atomic Masses**:
- The atomic mass of carbon (C) is approximately 12 u (atomic mass units).
- The atomic mass of hydrogen (H) is approximately 1 u.

3. **Calculate the Total Mass of Hydrogen**:
- Since there are four hydrogen atoms in methane, the total mass of hydrogen is:
\[ 4 \times 1 \, \text{u} = 4 \, \text{u} \]

4. **Calculate the Total Molecular Mass of Methane**:
- Now, add the mass of carbon and the total mass of hydrogen:
\[ \text{Molecular mass of CH₄} = \text{mass of C} + \text{mass of H} = 12 \, \text{u} + 4 \, \text{u} = 16 \, \text{u} \]

5. **Convert to Gram Molecular Mass**:
- The gram molecular mass (or molar mass) is numerically equal to the molecular mass in grams. Therefore, the gram molecular mass of methane is:
\[ 16 \, \text{g/mol} \]

### Final Answer:
The gram molecular mass of CH₄ (methane) is **16 g/mol**.

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