The following reaction is an example of a
`4NH_(3)(g) +5O_(2)(g) to 4NO(g) +6H_(2)O (g) `
(i) Displacement reaction
(ii) Combination reaction
(iii) Redox reaction
(iv) Neutralisation reaction

Options

A. (i) and (iv)
B. (ii) and (iii)
C. (i) and (iii)
D. (iii) and (iv)

Explanation

To determine the type of reaction represented by the equation:

\[ 4NH_3(g) + 5O_2(g) \rightarrow 4NO(g) + 6H_2O(g) \]

we will analyze the components of the reaction step by step.

### Step 1: Identify the Reactants and Products
The reactants in this reaction are ammonia (NH₃) and oxygen (O₂), while the products are nitrogen monoxide (NO) and water (H₂O).

**Hint:** Look at the substances involved in the reaction to identify what is being transformed.

### Step 2: Analyze the Changes in Oxidation States
- In ammonia (NH₃), nitrogen has an oxidation state of -3.
- In nitrogen monoxide (NO), nitrogen has an oxidation state of +2.
- Oxygen (O₂) has an oxidation state of 0, and in water (H₂O), it has an oxidation state of -2.

This indicates that nitrogen is being oxidized (increase in oxidation state from -3 to +2), and oxygen is being reduced (decrease in oxidation state from 0 to -2).

**Hint:** Check how the oxidation states of the elements change from reactants to products to identify oxidation and reduction.

### Step 3: Determine the Type of Reaction
1. **Displacement Reaction:** This involves one element displacing another in a compound. In this case, NH₃ is not displacing O₂, so it is not a displacement reaction.
2. **Combination Reaction:** This involves two or more reactants combining to form a single product. Here, we have multiple products, so it is not a combination reaction.
3. **Redox Reaction:** Since there are changes in oxidation states (oxidation of nitrogen and reduction of oxygen), this reaction is classified as a redox reaction.
4. **Neutralization Reaction:** This typically involves an acid reacting with a base to produce salt and water. This does not apply to the given reaction.

**Hint:** Consider the definitions of each type of reaction to see which one fits the observed changes in the reaction.

### Conclusion
The reaction \( 4NH_3(g) + 5O_2(g) \rightarrow 4NO(g) + 6H_2O(g) \) is an example of a **redox reaction**.

**Final Answer:** (iii) Redox reaction