Question

With increasing bond order, stability of a bond
a.) Remains unaltered
b.) Decreases
c.) Increases
d.) None of these

Answer 1

Hint: A bond order determines the number of bonds present in the molecule which also gives us information regarding bond length, stability and enthalpy values.

Complete Solution :
- The bond order is defined as the number of bonds between the two atoms in a molecule. In other words, the number of bonds attached to the compound gives the bond order.
- Bond order can be calculated using the following formula
\[BO=\dfrac{(\text{No}\text{. of electrons in antibonding M}\text{.O) - (No}\text{. of electrons in bonding M}\text{.O)}}{2}\]

- For example, in diatomic nitrogen, the bond order is 3, while in acetylene, the bond order between the two carbon atoms is 3 and the $C-H$ bond, order is 1.
- A high bond order indicates more attraction between electrons. And so, higher bond order shows that the atoms are held together more closely. Bond order also specifies the stability of a compound.
- As the bond order increases, atoms are held together more tightly. Since the bond becomes stronger, high energy is required to break the bond with the increase in enthalpy. And therefore, the stability of the compound also increases.
So, the correct answer is “Option C”.

Note: A bond order increases across a period and decreases down the group. Stable bonds usually have a positive bond order. As bond order refers to the bond strength it is used widely in valence bond theory.