wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

The formation of the oxide ion, O2(g), from oxygen atom requires first an exothermic and then an endothermic step as shown below:
O(g)+eO(g);ΔfH=141kJmol1
O(g)+eO2(g);ΔfH=+780kJmol1
Thus, process of formation of O2 in gas phase is unfavourable even though O2 is isoelectronic with neon. It is due to the fact that:

A
oxygen is more electronegative
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
addition of electron in oxygen results in larger size of the ion
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
electron repulsion outweighs the stability gained by achieving noble gas configuration
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
O ion has comparatively smaller size than oxygen atom
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B electron repulsion outweighs the stability gained by achieving noble gas configuration
The formation of the oxide ion, O2(g), from oxygen atom requires first an exothermic and then an endothermic step as shown below:
O(g)+eO(g);ΔfH=141 kJmol1
O(g)+eO2(g);ΔfH=+780 kJmol1
Thus, the process of formation of O2 in the gas phase is unfavorable even though O2 is isoelectronic with neon. It is due to the fact that electron repulsion outweighs the stability gained by achieving noble gas configuration.

When an electron is added to O anion, there is strong electrostatic repulsion between the two negative charges. Due to this, the second electron gain enthalpy of oxygen is positive.

flag
Suggest Corrections
thumbs-up
0
similar_icon
Similar questions
View More
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Electronegativity
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon