Question

The oxidation number of N and CI in noclo4 respectively are ??

Answer 1

for n
x-2-1-8=0
x-11=0
x=11
oxidation number for N=11
for cl
-3-2+x-8=0
x-13=0
x=13
oxidation number for cl=13

Answer 2

NOClO4 is an ionic compound which is made up of polyatomic ions NO+ (nitric oxide) and ClO4- (perchlorate). To work out the oxidation number:
-the sum of oxidation numbers must be equal to the charge of polyatomic numbers
-assign negative oxidation numbers to the most electronegative species

As ClO4 has a 1- charge, and each Oxygen's oxidation state is usually 2-, four oxygens amount to 8-. Since the final charge of the perchlorate ion is 1-, it means Cl should have a positive charge of +7 to balance the negatives (ie 7-8 = -1).

The oxidation number of N and CI in NOCLO4 respectively are +3 and +7