Which of the following is the most suitable replacement for CFCs in terms of reducing their environmental impact? (A) CH₄ (B) CH₂F₂ (C) CH₂ClF (D) CHCl₂CClF - HSC - SSCE Chemistry - Question 6 - 2015 - Paper 1

To determine the most suitable replacement for chlorofluorocarbons (CFCs), we need to consider the environmental impact of each option based on their ozone depletion potential (ODP) and global warming potential (GWP).

1. CH₄ (Methane): This gas has a low ODP, but its GWP is relatively high, contributing significantly to global warming. Therefore, it is not an ideal replacement for CFCs.

2. CH₂F₂ (Difluoromethane): This compound has a moderate ODP and lower GWP compared to methane. It is often regarded as a suitable alternative to CFCs as it possesses less potential for ozone layer depletion.

3. CH₂ClF (Hydrochlorofluorocarbon): This compound also has a significant ODP, though it is lower than that of CFCs. Its GWP is moderate, making it less favorable.

4. CHCl₂CClF (Other chlorinated hydrocarbons): This choice has a high ODP, similar to that of older CFCs, and would not be suitable as an alternative.

After evaluating all the options, (B) CH₂F₂ stands out as the most suitable replacement for CFCs due to its relatively low environmental impact.