Question

Which of the following has the highest boiling point?
(a)- Ne
(b)- He
(c)- \[C{{H}_{4}}\]
(d)- Xe

Answer 1

Hint: Among these, the highest boiling point is of the element from the noble gas group. It is used in gas-filled lamps because of the high boiling point it has low thermal conductivity. It is also used in high-speed photography.


Complete step by step solution:
Let us understand what is the boiling point: -
The boiling point of a substance is called when the vapor pressure of the substance is equal to the atmospheric pressure.
The boiling point is when the liquid state changes to the gaseous state.
Let us now study the boiling point of all options one by one:
Since all the options above are gases, their boiling points are very low.

(a)- Ne: This is neon. This is the second element of the noble gas group. Its boiling point is 27.1K.
(b)- He: This is helium. This is the first element of the noble gas group. Its boiling point is 4.2K.
(c)- $C{{H}_{4}}$: This is methane. It is the first member of the homologous series of alkanes. Its boiling point is 111.65K.
(d)- Xe: This is xenon. It is the fifth element of the noble gas group. Its boiling point is 165.0K.
So, by observing all the options we can see that Xe has the highest boiling point.

This is also because it is the fifth element of the noble gas group, its size is large. Due to its large size, it has a greater extent of van der Waals forces.
So, the correct answer is “Option D”.

Note: You may get confused between $C{{H}_{4}}$ and Xe because all the options are the only compound and rest are elements. Since compounds have a higher boiling point than elements. Xe has a higher boiling point because of its size and force of attraction.