Question

an oxide of nitrogen has a molecular weight of 30. total number of electrons in one molecule of the compound is a)15b)30c)45d)60

Answer 1

Hey !

Solution : Let the Molecular Formula = NₓOₓ

Molecular Formula = 30 u

Mass of Nitrogen = 14 u

Hence Molecular formula = Mass of Nitrogen + Mass of Oxygen 

=> 30 u = 14 ( x ) + 16 ( x )

=>  30 u = x ( 14 + 16 )

=> 30 u = 30 ( x )

Since molecular formula coincides, the value of x = 1.

Hence the Molecular formula = NO ( Nitrogen Oxide )

No of electrons = No of electrons in Nitrogen + No of electrons in Oxygen

No of electrons in Nitrogen = 7 

No of electrons in Oxygen = 8

Hence Total Number of Electrons = 8 + 7 = 15 electrons.

Hence Option ( a ) is correct.

Hope it helped !