Boiling is the changing of a liquid into vapor or gas. And the temperature at which this happens is called the boiling point of the substance. The boiling point of water is generally given as 100° centigrade, but the boiling point varies according to the pressure of the atmosphere. Water will boil at a lower temperature at the top of a mountain than at sea level. At the top of Mont Blanc, for instance, water boils at 85° centigrade.
Some substances boil at a very much higher temperature than water. Gold, for instance, melts or becomes liquid at 1063° centigrade, and boils at 2600°. Copper melts at 1083° centigrade and boils at 2300°. Silicon, which forms about a quarter of the Earth’s crust, melts at 1420° centigrade and boils at 2600°. Tin melts at 231° centigrade and boils at 2260°.
These are substances that are solid in the ordinary temperatures at which we live. Mercury, or quicksilver, which is normally liquid, boils at 375° centigrade. When we come to substances that are gases at ordinary temperatures, we find that their boiling point is very low. Hydrogen boils, or changes from the liquid into the gaseous state, at minus 253° centigrade. Fluorine boils at minus 187° centigrade; nitrogen at minus 196°, and oxygen at minus 183°.
The State change phenomenon is considered of vital importance in Science. All three states of matter namely solid, liquid and gas have their own devoted boiling and freezing points. A temperature where one atmosphere becomes equal to the vapor pressure of that particular liquid is known as boiling point. This is termed as the normal boiling point.
One of the substances that become cold on boiling is the Liquid Nitrogen. The temperature of Liquid nitrogen can be quickly frozen down to its freezing point that is -3460. Its handling and carriage involve thermal insulation. In order to transport or carry the liquid nitrogen, it is stored in vacuum flasks. These vacuum flasks maintain a constant temperature.
One of the abilities of liquid nitrogen is to maintain temperatures far below the freezing point. This important attribute makes it useful in a number of applications. It is utilized on a larger scale as a source of refrigeration.
There are a number of uses of liquid nitrogen. Some of them are listed below:
- In order to carry important laboratory experiments, liquid nitrogen can be very beneficial as it has the ability to store cells at very low temperatures.
- It can be used as a backup nitrogen resource in instruments related to fire prevention.
- It is converted and utilized as a source of dry nitrogen as well.
- Food items need to be frozen for prolong usage, Liquid nitrogen is considered important in not only freezing but transportation and immersion of food.
- The liquid nitrogen can be used as an alternative for a valve in blockage of fluid flow in large pipes.
- In achieving superconductivity and specially designed cameras for Astronomy, for super clocking in computing and related processes.
The culinary use of liquid is also a vital source of convenience. This particular value of the liquid nitrogen was first mentioned back in 1890. A recipe book contained this information and it was written by a writer named Mrs. Agnes Marshall.
Nowadays, the technique is so popular among restaurants that they use it to make frozen yogurts and other kinds of desserts because the phenomenal ability of the liquid nitrogen to cool food. It is also the main source of smooth texture found in desserts.
If we look into the details, the liquefaction of nitrogen was first performed back in 1883. The two scientists who performed the experiment were Zygmunt Wróblewski and Karol Olszewski from Poland.
The production of liquid nitrogen is carried out on a commercial basis. It might be produced for the direct sale or during the production of liquid oxygen it can be extracted as a byproduct. The plants which are dedicated to producing liquid nitrogen became common after the Second World War. On average, a modern plant these days usually produces 3000 tons of liquid gas on a daily basis.
Boiling point (Wikipedia)
Melting point (Wikipedia)