Complete combustion of hydrocarbon produces

Options

A. `CO + H_2O `
B. `CO + H_2`
C. `CO_2 + H`
D. `CO_2 + H_2O`

Explanation

To answer the question regarding the products of complete combustion of hydrocarbons, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hydrocarbons**: Hydrocarbons are organic compounds made up of hydrogen and carbon atoms. They can be in various forms, such as alkanes, alkenes, and alkynes.

**Hint**: Remember that hydrocarbons consist only of carbon (C) and hydrogen (H) atoms.

2. **Defining Combustion**: Combustion is a chemical reaction that occurs when a substance reacts with oxygen, producing heat and light. In the case of hydrocarbons, this reaction typically occurs in the presence of sufficient oxygen.

**Hint**: Combustion reactions require oxygen to proceed.

3. **Products of Complete Combustion**: In complete combustion, a hydrocarbon reacts with oxygen to produce carbon dioxide (CO2) and water (H2O). This occurs when there is enough oxygen available for the reaction.

**Hint**: Complete combustion yields CO2 and H2O as products.

4. **Example of a Hydrocarbon**: Taking methane (CH4) as an example, when it undergoes complete combustion, the reaction can be represented as:
\[ CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O \]
This shows that one molecule of methane reacts with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water.

**Hint**: Use the combustion of methane as a typical example to illustrate the reaction.

5. **General Formula**: The general formula for the complete combustion of any hydrocarbon (C_nH_m) can be represented as:
\[ C_nH_m + \left(\frac{m + 2n}{2}\right) O_2 \rightarrow n CO_2 + \frac{m}{2} H_2O \]
This formula indicates that the products will always be carbon dioxide and water, regardless of the specific hydrocarbon.

**Hint**: Familiarize yourself with the general formula for combustion of hydrocarbons.

### Final Answer:
The complete combustion of hydrocarbons produces carbon dioxide (CO2) and water (H2O).