Test Index

NCERT Class XII Chapter
Electrostatic Potential and Capacitance
Questions With Solutions

© examsnet.com
Question : 19
Total: 37
If one of the two electrons of a H2 molecule is removed, we get a hydrogen molecular ion H2+ . In the ground state of an H2+ , the two protons are separated by roughly 1.5 Å, and the electron is roughly 1 Å from each proton. Determine the potential energy of the system. Specify your choice of the zero of potential energy.
Solution:  
It is a system of three point charges and the potential energy stored is this system of charges is

U' =
1
4πε0
[
q1q2
r12
+
q1q3
r13
+
q2q3
r23
]
U = 9 × 109 [
e×−e
1
+
e×e
1.5
+
e×−e
1
] ×
1
10−10m
or U = 9 × 1099 × (1.6×10−19)2 × 1010[−1+
1
.5
−1] J
or U =
9×1019×(1.6×10−19)2
1.6×10−19
 × (−
2
1.5
) eV or U = - 19.2 eV
with zero potential energy at infinity
© examsnet.com
Go to Question:
Prev Question
Next Question