Question

Boiling point of nitrogen is:
(A) $- {166^o}C$
(B) $- {116^o}C$
(C) $- {196^o}C$
(D) $- {256^o}C$

Answer 1

Air is a mixture of different gases and dust particles. Percentages wise distribution of different gases are: Nitrogen - $78\%$ , Oxygen - $21\%$, Argon - $0.9\%$ and the remaining portion is occupied by various other gases like, carbon dioxide, neon, helium, sulphur dioxide etc. Air also contains water vapour. Amount of water vapour in air is called absolute humidity. This amount of space in air that can hold water changes depending on the temperature and pressure.

Complete answer: Air also contains water vapour. Amount of water vapour in air is called absolute humidity. This amount of space in air that can hold water changes depending on the temperature and pressure. Nitrogen gathers at its limit, $- {195.8^o}C$ or $- {196^o}C$ , to a dry fluid that is lighter than water.
Segments of air:The organization of air isn't steady and changes all around. For instance: in contaminated territories, since emanations of carbon dioxide are exceptionally high, air over there contains the higher level of carbon dioxide. The fundamental segments of air are clarified underneath:
Water vapour: We realize that water present in seas and streams vanishes during summer and escapes into the air. In this way water fumes are one of the parts of the air. It possesses an extremely less level of earth's environment.
Oxygen: Have you ever attempted to consume a flame without air? On the off chance that you would attempt you would see that it doesn't consume without air. Air contains some issues which underpin burning. This substance is oxygen. Oxygen is one of the significant parts of air around us. Air includes practically $21\%$ oxygen.
Nitrogen: When you blow over a consuming flame you notice that it douses. This implies air contains as well. This is significantly because of the presence of nitrogen. Nitrogen possesses almost $78\%$ of earth's air and is the most plentiful gas on our planet.
Carbon dioxide: Carbon dioxide is for the most part delivered because of breath by plants and creatures or consuming of fuel. It involves $0.038\%$ of the world's environment. Its inhabitants continue changing starting with one spot then onto the next in our climate.
Smoke and residue particles: Smoke is available in our air because of the consuming of fills. Its inhabitants fluctuate here and there. It is a combination of gases and is regularly hurtful. Aside from these, dust particles are likewise present in our environment which we see when we see a beam of light in a dull room. Smoke and residue particles involve under $1\%$ of earth's environment.

Hence the correct answer is (C).

Note: The diatomic character of the ${N_2}$ particle is held after liquefaction. The frail van der Waals collaboration between the ${N_2}$ atoms brings about little interatomic connection, shown in its low limit. The temperature of fluid nitrogen can promptly be diminished to its edge of freezing over $63K$ by putting it in a vacuum chamber siphoned by a vacuum siphon.