Oxidation Number

Question 1

Law 1

Answer 1

Oxidation of an element in an elementary substance is 0. i.e. O2 = 0 and P4 = 0

Question 2

Law 2

Answer 2

Oxidation # of a monoatomic ion is = to the charge. i.e. Cl- = -1 and Na+ = +1

Question 3

Law 3

Answer 3

Certain elements (Leading elements) have same oxidation number in all compounds. Group 1 = +1, Group 2 = +2 and Fluorine (F) = -1

Question 4

Law 4

Answer 4

Hydrogen in a compound has oxidation = 1, unless it’s combined with a metal, then it = -1. i.e. HCl vs NaH

Question 5

Law 5

Answer 5

Sum of the oxidation numbers in a neutral species = 0 and in a polyatomic ion is equal to the charge. NO3- = -1, O = -2 and N = +5

Question 6

Law 6

Answer 6

Oxidation # of Oxygen = -2 unless it’s combined with a group 1 metal, then it’s always -1. i.e. K2O2.