Which of the following has the lowest freezing point temperature?
Freon-22
Understanding Freezing Points of Common Refrigerants
The question asks us to identify which of the given substances has the lowest freezing point temperature. We are provided with four options: Freon-11, Freon-12, Freon-22, and Ammonia. These substances are commonly used as refrigerants in various cooling systems.
To answer this question, we need to know the typical freezing point temperatures for each of these refrigerants. The freezing point is the temperature at which a liquid turns into a solid at a standard pressure.
Let's list the approximate freezing points for each substance:
| Refrigerant | Chemical Formula | Approximate Freezing Point ($^\circ$C) | Approximate Freezing Point ($^\circ$F) |
|---|---|---|---|
| Freon-11 | CCl$_3$F | -111.0 | -167.8 |
| Freon-12 | CCl$_2$F$_2$ | -157.7 | -251.9 |
| Freon-22 | CHClF$_2$ | -160.0 | -256.0 |
| Ammonia | NH$_3$ | -77.7 | -107.8 |
Now, comparing these values to find the lowest temperature:
- Freon-11: -111.0 $^\circ$C
- Freon-12: -157.7 $^\circ$C
- Freon-22: -160.0 $^\circ$C
- Ammonia: -77.7 $^\circ$C
When comparing negative numbers, the lowest temperature is the one with the largest absolute value. In this list, -160.0 $^\circ$C is the lowest temperature among the options.
This lowest freezing point corresponds to Freon-22.
Therefore, Freon-22 has the lowest freezing point temperature among the given options.
Important Questions from Refrigerants
Which of the following instruments is commonly used to detect leaks in refrigeration systems using halogenated refrigerants?
The commonly used refrigerant in domestic refrigerators is:
Pure refrigerant vapour is obtained for the condenser in a vapour absorption cooling system:
An undesirable property of a refrigerant is its:
A mixture of refrigerants having a fixed boiling point is called:
