Ammonia is used as a refrigerant not ph3 why...?

The reason ammonia (NH3) is used as a refrigerant rather than phosphine (PH3) is because ammonia has certain properties that make it a suitable and widely used choice in refrigeration systems.

1. Thermodynamic Properties: Ammonia has excellent thermodynamic properties that make it an efficient refrigerant. It has a relatively high latent heat of vaporization, which means that it can absorb a significant amount of heat when it evaporates. This property allows it to cool its surroundings effectively.

2. Non-toxicity: One of the most important factors in choosing a refrigerant is its safety. Ammonia is relatively non-toxic, especially when compared to phosphine. It has a well-established safety record and is widely used in industrial and commercial refrigeration applications without major concerns.

3. Environmental Impact: Ammonia has a relatively low impact on the environment compared to other refrigerants. It has zero ozone depletion potential (ODP) and a low global warming potential (GWP), making it a more environmentally friendly choice.

4. Cost-effectiveness: Ammonia is readily available and cost-effective compared to other refrigerants. It has been used for many years in various refrigeration applications, and the infrastructure for handling and storing ammonia is well-established.

On the other hand, phosphine (PH3) is highly toxic, flammable, and poses significant safety risks when used as a refrigerant. Its toxic nature and safety concerns make it impractical and hazardous for commercial or industrial applications.

In conclusion, ammonia is preferred as a refrigerant due to its favorable thermodynamic properties, non-toxicity, low environmental impact, and cost-effectiveness compared to phosphine.