Match the following :
Coloumn -I – Coloumn-II
(A)CFC – (i) Green House Effect
(B)Co2 – (ii) Most available gas
(C)N2 – (iii) Poisonous gas (Toxic Gas)
(D)CO – (iv)Ozone depletion

Question

Match the following :
 Coloumn -I –                       Coloumn-II 
(A)CFC      –                          (i) Green House Effect 
(B)Co2    –                            (ii) Most available gas 
(C)N2    –                              (iii) Poisonous gas (Toxic Gas) 
(D)CO –                                (iv)Ozone depletion

Accepted Answer

Option 4 is the correct answer for the given question, and here's why:

1. **CFC (Chlorofluorocarbons) - Ozone Depletion (iv):**  
   CFCs are compounds that were commonly used in refrigeration, air conditioning, and aerosol propellants. They are known to cause significant damage to the ozone layer when they are released into the atmosphere. The chlorine atoms in CFCs react with ozone (O3) molecules, leading to the depletion of the ozone layer, which protects the Earth from harmful ultraviolet radiation. Therefore, CFCs are correctly matched with ozone depletion.

2. **CO2 (Carbon Dioxide) - Greenhouse Effect (i):**  
   Carbon dioxide is a major greenhouse gas that contributes to the greenhouse effect. It traps heat in the Earth's atmosphere, leading to global warming and climate change. The increase in CO2 levels due to human activities such as burning fossil fuels and deforestation is a primary driver of the enhanced greenhouse effect. Thus, CO2 is accurately associated with the greenhouse effect.

3. **N2 (Nitrogen) - Most Available Gas (ii):**  
   Nitrogen is the most abundant gas in the Earth's atmosphere, making up about 78% of the air we breathe. It is a relatively inert gas and does not easily react with other substances under normal conditions. This makes it the most available gas in the atmosphere, justifying its match with this description.

4. **CO (Carbon Monoxide) - Poisonous Gas (Toxic Gas) (iii):**  
   Carbon monoxide is a colorless, odorless, and highly toxic gas. It is produced by the incomplete combustion of carbon-containing fuels. CO can bind with hemoglobin in the blood, preventing oxygen from being transported effectively throughout the body, which can be fatal. Therefore, CO is correctly identified as a poisonous or toxic gas.

**Explanation of Incorrect Options:**

- **Option 1:** Incorrect because it mismatches all the pairs. For example, CFC is not primarily associated with the greenhouse effect, and CO2 is not the most available gas.
- **Option 2:** Incorrect because it incorrectly associates CFC with being a poisonous gas and CO2 with the most available gas, which are not accurate.
- **Option 3:** Incorrect because it wrongly matches CFC with being a poisonous gas and CO2 with ozone depletion, which are not their primary environmental impacts.

In conclusion, Option 4 correctly matches each substance with its most relevant environmental impact or characteristic, making it the correct answer.