The poisonous gas that comes out with petrol burning in a car is

Options

A. `CH_(4)`
B. `C_(2)H_(4)`
C. `CO_(2)`
D. CO

Answer

To answer the question regarding the poisonous gas that comes out with petrol burning in a car, we can follow these steps:

### Step 1: Understand the combustion of petrol
When petrol (which is primarily composed of hydrocarbons) burns in an engine, it undergoes a chemical reaction with oxygen. This process is known as combustion.

**Hint:** Remember that combustion typically involves hydrocarbons reacting with oxygen to produce various products.

### Step 2: Identify the products of combustion
The complete combustion of hydrocarbons ideally produces carbon dioxide (CO2) and water (H2O). However, due to incomplete combustion, which can occur in car engines, other products can also be formed.

**Hint:** Consider what happens when there is insufficient oxygen for complete combustion.

### Step 3: Recognize the harmful products
In the case of incomplete combustion, carbon monoxide (CO) is produced alongside carbon dioxide and water. Carbon monoxide is a colorless, odorless gas that is highly toxic to humans.

**Hint:** Think about which of the combustion products is known for being particularly dangerous to health.

### Step 4: Evaluate the options given in the question
The options provided are:
- CH4 (Methane)
- C2H4 (Ethylene)
- CO2 (Carbon Dioxide)
- CO (Carbon Monoxide)

From these options, we need to identify which one is the poisonous gas.

**Hint:** Recall that while CO2 is a product of combustion, it is not poisonous in the same way that CO is.

### Step 5: Conclude with the correct answer
Based on the information gathered, the poisonous gas that comes out with petrol burning in a car is carbon monoxide (CO).

**Final Answer:** The poisonous gas that comes out with petrol burning in a car is **carbon monoxide (CO)**.

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