Give suitable explanations for the following :
(a) SF₆ is used as a gaseous electrical insulator.
(b) NO becomes brown when released in air.
(c) NO is paramagnetic in the gaseous state but diamagnetic in the liquid and solid states.
Answers
a)It is a non-toxic gas which is thermally stable and chemical inert.
Due to its inertness and high tendency to suppress internal discharges, it is used as a gaseous electrical insulator
b)Nitric oxide combines with oxygen when exposed to air to give nitrogen dioxide which is brown in colour.
c)The number of electrons in Nitrogen are 7 and in oxygen are 8. Hence the number of electrons that would be present in the molecular orbitals in NO are 7 + 8 = 15. As the number of electrons are odd, all the electrons in NO molecule cannot be paired. Hence, a single electron would be present in a π*2p orbital. Therefore NO is an odd electron species and the gas is hence paramagnetic due to the presence of unpaired electron. In the liquid and the solid state, the gas dimerises. The unpaired electron becomes paired and NO is therefore diamagnetic
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