Find the oxidation number of carbon in the following compounds: `CH_(3)OH, CH_(2)O, HCOOH, C_(2)H_(2)`.

Explanation

To find the oxidation number of carbon in the given compounds, we will follow a systematic approach for each compound.

### Step-by-Step Solution:

1. **For CH₃OH (Methanol)**:
- Let the oxidation number of carbon be \( X \).
- The oxidation numbers of hydrogen (H) is +1 and oxygen (O) is -2.
- The equation based on the sum of oxidation numbers is:
\[ X + (3 \times +1) + (-2) + (+1) = 0 \]
- Simplifying the equation:
\[ X + 3 - 2 + 1 = 0 \implies X + 2 = 0 \implies X = -2 \]
- **Oxidation number of carbon in CH₃OH is -2.**

2. **For CH₂O (Formaldehyde)**:
- Let the oxidation number of carbon be \( X \).
- The oxidation numbers are the same: H is +1 and O is -2.
- The equation is:
\[ X + (2 \times +1) + (-2) = 0 \]
- Simplifying:
\[ X + 2 - 2 = 0 \implies X = 0 \]
- **Oxidation number of carbon in CH₂O is 0.**

3. **For HCOOH (Formic Acid)**:
- Let the oxidation number of carbon be \( X \).
- The oxidation numbers are: H is +1 and O is -2.
- The equation is:
\[ X + (+1) + (-2) + (-2) + (+1) = 0 \]
- Simplifying:
\[ X + 1 - 2 - 2 + 1 = 0 \implies X - 2 = 0 \implies X = +2 \]
- **Oxidation number of carbon in HCOOH is +2.**

4. **For C₂H₂ (Acetylene)**:
- Let the oxidation number of carbon be \( X \).
- There are two carbon atoms, and the oxidation number of hydrogen is +1.
- The equation is:
\[ (2X) + (2 \times +1) = 0 \]
- Simplifying:
\[ 2X + 2 = 0 \implies 2X = -2 \implies X = -1 \]
- **Oxidation number of carbon in C₂H₂ is -1.**

### Summary of Oxidation Numbers:
- **CH₃OH**: -2
- **CH₂O**: 0
- **HCOOH**: +2
- **C₂H₂**: -1