Question

What is the oxidation state of S in the following compound?

Na₂S₂O₃

Answer 1

The oxidation state of sodium (Na) is +1.

There are 2 sodium atoms, so the total oxidation state of Na is +2.

The oxidation state of oxygen (O) is –2.

There are 3 oxygen atoms, so the total oxidation state of O is –6.

For neutral compounds, the total charge is 0.

2(+1) + 2x + 3(–2) = 0

⇒ 2 + 2x – 6 = 0

⇒ 2x – 4 = 0

⇒ 2x = 4

⇒ x = +2

∴ The oxidation state of S in Na₂S₂O₃ is +2.