Refer to the given passage and answer the following questions.
When alcohols react with carboxylic acids in the presence of concentrated sulphuric acid, compounds with fruity smell called esters are formed. Also, alcohols on oxidation in the presence of acidified `K_2 ,Cr_2,O_7` , form carboxylic acids.
Which of the following statements is/are correct regarding these two compounds?
I. They both react with sodium metal to evolve a combustible gas.
II. They both react with `NaHCO_3` to evolve a gas which turns lime water milky.
III. They both turn blue litmus red.

Options

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

Answer

To solve the question, we need to analyze the statements regarding alcohols and carboxylic acids based on the information provided in the passage.

### Step-by-Step Solution:

1. **Understanding the Reaction with Sodium Metal:**
- Alcohols react with sodium metal to produce sodium alkoxide and hydrogen gas (H₂).
- For example, ethanol (C₂H₅OH) reacts with sodium to form sodium ethoxide (C₂H₅ONa) and hydrogen gas (H₂).
- Carboxylic acids also react with sodium metal in a similar manner, producing sodium carboxylate and hydrogen gas.
- **Conclusion:** Both alcohols and carboxylic acids react with sodium metal to evolve a combustible gas (H₂).
- **Statement I is correct.**

2. **Understanding the Reaction with Sodium Bicarbonate (NaHCO₃):**
- Carboxylic acids react with sodium bicarbonate to produce carbon dioxide (CO₂), water, and sodium salt of the acid.
- For example, acetic acid (CH₃COOH) reacts with NaHCO₃ to produce sodium acetate (CH₃COONa), water, and carbon dioxide (CO₂), which turns lime water milky.
- Alcohols do not react with sodium bicarbonate to produce CO₂.
- **Conclusion:** Only carboxylic acids react with NaHCO₃ to evolve a gas that turns lime water milky.
- **Statement II is incorrect.**

3. **Understanding the Effect on Litmus Paper:**
- Carboxylic acids are acidic and will turn blue litmus paper red.
- Alcohols are generally neutral and do not affect litmus paper.
- **Conclusion:** Only carboxylic acids turn blue litmus red.
- **Statement III is incorrect.**

### Final Conclusion:
- **Correct Statements:** Only Statement I is correct.
- **Incorrect Statements:** Statements II and III are incorrect.