Which of the following statements is`//`are correct about the following reactions?
I. `C_(6)H_(12)O_(6)overset(H_(2)SO_(4)(conc))rarr6C+6H_(2)O`
II. `H_(2)SO(dil)+ZnCO_(3)rarrZn^(2+)+CO_(2)+SO_(4)^(2-)+H_(2)O`
III. `H_(2)SO_(4)(dil)+ZnrarrZn^(2+)+H_(2)+SO_(4)^(2-)`
IV. `5H_(2)SO_(4)(conc)+4ZnrarrH_(2)S+4Zn^(2+)+4SO_(4)^(2-)+4H_(2)O`

Options

A. In reaction (I), `H_(2)SO_(4)` acts as a dehydrating agent.
B. In reaction (II), `H_(2)SO_(4)` acts as an acid.
C. In reaction (III), `H_(2)SO_(4)` acts both as an acid and an oxidising agent.
D. In reaction (IV), `H_(2)SO_(4)`, acts as an oxidising agent.

Explanation

To determine which statements are correct regarding the given reactions, we will analyze each reaction step by step.

### Step 1: Analyze Reaction I
**Reaction:** \( C_6H_{12}O_6 \overset{H_2SO_4 (conc)}{\rightarrow} 6C + 6H_2O \)

- **Observation:** In this reaction, concentrated sulfuric acid (H₂SO₄) acts as a dehydrating agent. It removes water from glucose (C₆H₁₂O₆), resulting in the formation of carbon (C) and water (H₂O).
- **Conclusion:** H₂SO₄ acts as a dehydrating agent in this reaction.

**Hint:** Concentrated sulfuric acid removes water from glucose, indicating its role as a dehydrating agent.

### Step 2: Analyze Reaction II
**Reaction:** \( H_2SO_4 (dil) + ZnCO_3 \rightarrow Zn^{2+} + CO_2 + SO_4^{2-} + H_2O \)

- **Observation:** In this reaction, dilute sulfuric acid (H₂SO₄) donates protons (H⁺ ions) to react with zinc carbonate (ZnCO₃). This behavior is characteristic of acids.
- **Conclusion:** H₂SO₄ acts as an acid in this reaction.

**Hint:** Dilute sulfuric acid donates protons, confirming its role as an acid.

### Step 3: Analyze Reaction III
**Reaction:** \( H_2SO_4 (dil) + Zn \rightarrow Zn^{2+} + H_2 + SO_4^{2-} \)

- **Observation:** Here, dilute sulfuric acid donates protons to zinc (Zn), leading to the formation of hydrogen gas (H₂) and zinc ions (Zn²⁺). Zinc is oxidized from 0 to +2 oxidation state.
- **Conclusion:** H₂SO₄ acts both as an acid (donating H⁺) and as an oxidizing agent (facilitating the oxidation of Zn).

**Hint:** The dual role of H₂SO₄ as an acid and oxidizing agent is evident from the reaction with zinc.

### Step 4: Analyze Reaction IV
**Reaction:** \( 5H_2SO_4 (conc) + 4Zn \rightarrow H_2S + 4Zn^{2+} + 4SO_4^{2-} + 4H_2O \)

- **Observation:** In this reaction, concentrated sulfuric acid is involved in the oxidation of zinc to zinc ions (Zn²⁺) and the reduction of sulfuric acid to hydrogen sulfide (H₂S). This indicates that H₂SO₄ is acting as an oxidizing agent.
- **Conclusion:** H₂SO₄ acts as an oxidizing agent in this reaction.

**Hint:** The conversion of sulfuric acid to hydrogen sulfide indicates its role as an oxidizing agent.

### Final Conclusion
Based on the analysis of all four reactions, we can conclude that:
- **Statement I:** Correct (H₂SO₄ acts as a dehydrating agent)
- **Statement II:** Correct (H₂SO₄ acts as an acid)
- **Statement III:** Correct (H₂SO₄ acts as both an acid and an oxidizing agent)
- **Statement IV:** Correct (H₂SO₄ acts as an oxidizing agent)

Thus, all statements (I, II, III, IV) are correct.

### Summary of Correct Statements
- **All statements (I, II, III, IV) are correct.**