Which of the following is example of combination reaction?

Options

A. `H_(2) + C1_(2) to 2HC1`
B. n-Hexane `overset (A1C1_(3)) (rarr)` neo hexane
C. `Zn + H_(2) SO_(4) to ZnSO_(4) + H_(2)`
D. `N_(2)O_(4) to 2NO_(2)`

Answer

To determine which of the following is an example of a combination reaction, we first need to understand what a combination reaction is. A combination reaction occurs when two or more reactants combine to form a single product.

### Step-by-Step Solution:

1. **Define Combination Reaction**: A combination reaction is defined as a chemical reaction where two or more substances (elements or compounds) combine to form a single product. The general form can be represented as:
\[ A + B \rightarrow AB \]

2. **Identify the Given Options**: We need to look at the options provided (though they are not listed in the question) and identify if any of them represent a combination reaction.

3. **Analyze the First Reaction**: For example, if we consider the reaction of hydrogen gas (H₂) and chlorine gas (Cl₂):
\[ H_2 + Cl_2 \rightarrow 2HCl \]
Here, hydrogen and chlorine combine to form hydrochloric acid (HCl). This is a clear example of a combination reaction.

4. **Check Other Options**: We must analyze the other options to see if they involve the combination of two or more reactants to form a single product. If any of the other options involve the formation of multiple products or do not combine two reactants, they will not qualify as combination reactions.

5. **Conclusion**: After analyzing all options, we conclude that the reaction between hydrogen and chlorine (H₂ + Cl₂ → HCl) is indeed a combination reaction, while the others do not fit the criteria.

### Final Answer:
The example of a combination reaction is the reaction between hydrogen gas (H₂) and chlorine gas (Cl₂) to form hydrochloric acid (HCl).

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