Match each oxoanion on the left with the correct oxidation number of its central element o… — JAMB UTME

Match each oxoanion on the left with the correct oxidation number of its central element on the right.

The correct matches pair

PO_4^{3-}

with

+5

NO_2^-

with

+3

SO_4^{2-}

with

+6

, and

CO_3^{2-}

with

+4

Each central atom's oxidation state is determined by setting the sum of the oxidation states equal to the net ionic charge, using

-2

for each oxygen atom.

Assign the standard oxidation number of

-2

to oxygen in oxoanions.

Each oxygen atom contributes an oxidation state of

-2

Oxygen is more electronegative than phosphorus, nitrogen, sulfur, and carbon.

Set up an algebraic sum where the total oxidation numbers equal the ion's net charge.

For

PO_4^{3-}

P + 4(-2) = -3

; for

NO_2^-

N + 2(-2) = -1

; for

SO_4^{2-}

S + 4(-2) = -2

; for

CO_3^{2-}

C + 3(-2) = -2

The sum of oxidation states in a polyatomic species equals the charge on the species.

Solve each linear equation for the oxidation number of the central atom.

P = +5

N = +3

S = +6

, and

C = +4

Algebraic isolation of the unknown variable determines the oxidation state.

Assigning Oxidation Numbers in Polyatomic Oxoanions

Question