Question

the total number of electrons in 4.2g of N3- ion is(NA IS THE AVAGARDO NO.)1)2.1 NA2)4.2 NA3)3NA4)3.2NA

Answer 1

given mass = 4.2 g
molecular mass = 14*3=42
no of o2 atom = givenmass /molecular mass *NA*atomicity
                       = 4.2/42*NA*3
                       = .3 NA