In which of the following reactions, water is not formed as one of the products?
I. Propanol is oxidised by acidified `K_(2)Cr_(2)O_(7)`
II. Ethanol undergoes complete combustion.
III. Methanoic acid reacts with anhyd. `Na_(2)CO_(3)`.
IV. Methanol reacts with sodium metal.

Options

A. III only
B. I, II and III only
C. III and IV only
D. IV only

Answer

To determine which of the following reactions does not produce water as one of the products, we will analyze each reaction step by step.

### Step 1: Analyze Reaction I
**Reaction**: Propanol is oxidized by acidified `K2Cr2O7`.

- **Propanol Structure**: CH3CH2CH2OH (1-propanol).
- **Oxidation Reaction**: When propanol is oxidized, it converts to propanal (an aldehyde).
- **Balanced Reaction**:
\[ CH3CH2CH2OH + [O] \rightarrow CH3CHO + H2O \]
- **Water Formation**: Water is produced in this reaction.

### Step 2: Analyze Reaction II
**Reaction**: Ethanol undergoes complete combustion.

- **Ethanol Structure**: C2H5OH.
- **Combustion Reaction**: Ethanol reacts with oxygen to produce carbon dioxide and water.
- **Balanced Reaction**:
\[ C2H5OH + 3O2 \rightarrow 2CO2 + 3H2O \]
- **Water Formation**: Water is produced in this reaction.

### Step 3: Analyze Reaction III
**Reaction**: Methanoic acid reacts with anhydrous `Na2CO3`.

- **Methanoic Acid Structure**: HCOOH.
- **Reaction with Na2CO3**: This reaction produces sodium formate and releases carbon dioxide and water.
- **Balanced Reaction**:
\[ HCOOH + Na2CO3 \rightarrow HCOONa + H2O + CO2 \]
- **Water Formation**: Water is produced in this reaction.

### Step 4: Analyze Reaction IV
**Reaction**: Methanol reacts with sodium metal.

- **Methanol Structure**: CH3OH.
- **Reaction with Sodium**: This reaction produces sodium methoxide and hydrogen gas.
- **Balanced Reaction**:
\[ 2CH3OH + 2Na \rightarrow 2CH3ONa + H2 \]
- **Water Formation**: No water is produced in this reaction.

### Conclusion
From the analysis:
- **Reactions I, II, and III** produce water.
- **Reaction IV** does not produce water.

Thus, the answer to the question is that **water is not formed in Reaction IV**.

### Final Answer
**The correct option is Reaction IV.**

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