What is the temperature of liquid nitrogen?

In this brief article, we will address the query,”What is the temperature of liquid nitrogen?” We will look at some potential hazards of liquid nitrogen. We will also briefly discuss the uses of liquid nitrogen.

What is the temperature of liquid nitrogen?

Liquid nitrogen is super cold with a temperature of −195.79 °C (77 K; −320 °F) which is the boiling point of nitrogen. Nitrogen can exist as a liquid between the temperatures 63 K and 77.2 K (-346°F and -320.44°F). Below these temperatures it becomes solid, at temperatures above its boiling point, nitrogen becomes a gas.

Liquid nitrogen much resembles boiling water and it can be stored for a few weeks in a dewar which is a pressurized and vented vessel. Because of its boiling temperature of -320 °F (-195.7º C), liquid nitrogen usually turns into vapor very fast when it’s released into the atmosphere at room temperature.

Is liquid nitrogen safe?

Liquid nitrogen is not toxic at all but because it is very cold, it does come with some potential hazards. Let us take a look at some of them.

It can lead to breathing problems  or hypoxia (low oxygen concentration in body tissues)

As liquid nitrogen turns into a gas, it increases its concentration in the area and thus results in a decrease in concentration of other gasses more so near the floor because warm gasses are lighter than cold gasses.

Let’s look at an example of liquid nitrogen being used to create a fog effect in a pool party, the temperature of the pool is not affected but if liquid nitrogen is used the excess nitrogen will tend to be blown away by air. 

This can lead to the concentration of oxygen at the surface of the pool reducing to a level where it results in hypoxia or breathing problems.

Risk of bursting

Another hazard of liquid nitrogen is its ability to expand. It can expand to 174.6 times its original volume when it changes phase to a gas. The gas expands another 3.7 times as it becomes warm to room temperature.

This brings the sum total increase to 645.3 times which means that vaporizing nitrogen usually exerts a lot of pressure on its surrounding. Liquid nitrogen must never be kept in a sealed container because of the risk of bursting.

It can cause frostbites (injury as a result of freezing of the skin and underlying tissues)

As previously mentioned, liquid nitrogen is very cold and this can result in harm to the human tissues. Liquid nitrogen vaporizes very fast and a small amount will bounce off the skin however a large volume of liquid nitrogen can result in frostbites.

Always ensure that you wear appropriate Personal Protective Equipment (PPEs) when you are handling liquid nitrogen so as to prevent any contact or inhalation of the extremely cold vapor. 

Risk of oxidation of organic matter

Liquid nitrogen containers can accumulate oxygen that is a condensate from the surrounding air. As the nitrogen evaporates, this presents a risk of vigorous oxidation of the organic matter.

What are the uses of liquid nitrogen?

Liquid nitrogen has a variety of uses due to its cold temperature. It can be used on the below:

  • It is used in the freezing and transportation of food materials.
  • It is used as a coolant for superconductors, vacuum pumps and other equipment.
  • When valves are not available, it is used as a fast way to freeze water or pipes to allow them to be worked on.
  • It is used in the cryopreservation of biological samples such as sperms, eggs etc
  • It is used in cryosurgery to freeze and remove any abnormal tissue.
  • It is used to cool materials for ease of machining or fracturing.
  • It is used in the molecular gastronomy preparation of unusual foods and beverages.
  • It is used to shield material away from any oxygen exposure.
  • It is used in the branding of cattle.

Conclusion

In this brief article, we have addressed the query,”What is the temperature of liquid nitrogen?” We have looked at some potential hazards of liquid nitrogen. We have also briefly discussed the uses of liquid nitrogen.

Citations

Leave a Comment