Which of the following bonds is least polar?
a. HO
b. H-N
C.H-B
d. H-C
e. HF
The correct answer and explanation is :
The least polar bond among the options is d. H-C.
Explanation:
To determine the polarity of a bond, we need to compare the electronegativities of the atoms involved. The greater the difference in electronegativity between the two atoms, the more polar the bond is. Let’s examine the electronegativity values of the atoms involved in each bond:
- H-O (Hydroxyl group): The electronegativity of Oxygen (O) is 3.44, and that of Hydrogen (H) is 2.20. The difference is 1.24, which makes this bond quite polar.
- H-N (Amine group): The electronegativity of Nitrogen (N) is 3.04, and that of Hydrogen (H) is 2.20. The difference is 0.84, making this bond less polar than the H-O bond but still quite polar.
- H-B (Boron-Hydrogen bond): The electronegativity of Boron (B) is 2.04, and that of Hydrogen (H) is 2.20. The difference is only 0.16, which makes this bond much less polar than the previous two.
- H-C (Hydrocarbon bond): The electronegativity of Carbon (C) is 2.55, and that of Hydrogen (H) is 2.20. The difference is only 0.35, making this bond the least polar among the options.
- H-F (Hydrogen-Fluoride bond): The electronegativity of Fluorine (F) is 3.98, and that of Hydrogen (H) is 2.20. The difference is 1.78, which is the largest difference in the list, making this bond the most polar.
Since the H-C bond has the smallest electronegativity difference (0.35), it is the least polar of the given options. In contrast, bonds like H-O and H-F have much higher polarity due to the larger electronegativity differences between the atoms involved.
Here is an infographic showing the electronegativity values for the different elements in the bonds and their corresponding differences. As you can see, the H-C bond has the smallest electronegativity difference, making it the least polar among the options.