Oxidation numbers Negative and Positive which one in these compounds?

Question

Can you tell me which element in the compound has the positive oxidation number and which has the negative oxidation number

A.
NH3

B.
HCI

C.
NO2

D.
NaCI

E.
SO2

F.
MnO2

Answer 1

A
N is negative

B
Cl is negative

C
O is negative

D
Cl is negative

E
O is negative

F
O is negative

Next time just look up the table of electronegativity. The element with the higher electronegativity will be negative. F, O, Cl and N are the four most electronegative elements, in decreasing order.

Answer 2

The previous answers are all best answers, and you should choose them. Just remember that H is always +1 except in hydrides like NaH, sodium hydride, where it is -1. O is always -2 except in peroxides like H2O2, hydrogen peroxide, where it is -1. The oxidation number of any element in the elemental state is 0, including H2 and O2. The oxidation numbers of all elements in a neutral compound have to add up to 0. Those in an ion have to add up to the charge on the ion.

Answer 3

NH3=N is -3 and H is +3
HCI= H is +1 and CI is -1
NO2=N is +4 and O is -2 (O2 = -4)
NaCl= Na is +1 and Cl is-1
SO2= S is +4 and O is -2 (O2=-4)
MnO2= Mn is +4 and O is -2( O2=-4)


I hope this helps!!