Liquid Nitrogen Temperature – minus 196 Celsius, 77 kelvin – but this is not the whole story, because this is the temperature that liquid nitrogen boils at so it could be considerably colder than that.
Like and element Nitrogen has three phases, solid, liquid and gas. The “normal” state of nitrogen is that of a gas – that is most of what we inhale/exhale. Approximately 80% of the atmosphere is made up of nitrogen gas. To make nitro ice cream, liquid nitrogen is used.
The temperature of liquid nitrogen depends upon pressure – at atmospheric pressure this must be below -196 °C. By increasing the pressure, then it is possible to make liquid nitrogen at a higher temperature – this is how the nitrogen is separated from the air in the first place. It cannot be stored in small quantities as a liquid because in order to keep the pressure it would obviously need to be a stored in a sealed container – but in order to use, the release of pressure would cause rapid boiling and much of the gas would be lost.
Instead the liquid nitrogen is stored in vacuum flasks that insulate is from heat, but allow it to evaporate as needed. This wau it can be stored for up to a week if well insulated.
Because the liquid nitrogen is open to the atmosphere then as it evaporates it releases heat energy which in turn will keep the liquid cool – it is effectively held at it boiling point of -195 degrees Celsius.