Which of the following compounds has the highest boiling point?

compounds
boiling-point

#1

Which of the following compounds has the highest boiling point?

1. F2
2. NaF
3. HF
4. ClF

Concepts and reason
Temperature at which a solid substance is convert into liquid is said to be boiling point.
First identify the polar and nonpolar compounds in the given. Select the molecule that has highest boiling point based on polar and nonpolar of the compounds.
Polar compounds show more boiling points than the nonpolar compounds.

Fundamentals
Bond between the atoms that have different electronegativities is called as polar bond.
Bond between the atoms that have same or similar electronegativities is called as nonpolar bond.
Covalent chemical bond is nonpolar in nature; whereas ionic chemical bond is polar.

Answer:

The homonuclear diatomic molecule image is nonpolar.
The hetero nuclear diatomic molecule NAF is polar.
The hetero nuclear diatomic molecule HF is polar.
The hetero nuclear diatomic molecule CIF is polar.

The molecule image is homonuclear diatomic molecule. In this molecule both the fluorine atoms have same electron negativity. There is no chance for the separation of charges. So, the bond between them becomes nonpolar.

The moleculesNAF,HF and CIF are hetero nuclear diatomic molecules. The atoms present between them have different electron negativities. Hence, there will be separation of charges. So, the bond between them becomes polar.

The molecule NAF has highest boiling point.
Compounds that has highest boiling point is NAF

The moleculeis NAF is polar covalent in nature. Due to its covalent nature, the electrons mutually shared between the bonded atoms. So, more energy is required to break the bonds between them. Consequently, boiling of the compound will be high.
In case of molecules NAF,HF and CIF ionic interactions are observed. Due to these weak ionic bonding interactions boiling points will below.

Compounds that has highest boiling point is NAF.