Numford
Oxidation number

S in H₂S

S is −2 in hydrogen sulphide.

Oxidation number

Type a formula or an ion: K2Cr2O7, Cr2O7 2-, MnO4-, NH4+ or K4[Fe(CN)6]. Put a known ion in brackets when two elements are unknown. Pick an element to solve for it.

S−2

  1. Hydrogen is +1 when bonded to non-metals.
  2. The oxidation numbers add up to the charge, 0: 2(+1) + x = 0.
  3. x = −2.
Rule steps

How to find it

  1. Hydrogen is +1 when bonded to non-metals.
  2. The oxidation numbers add up to the charge, 0: 2(+1) + x = 0.
  3. x = −2.
Every atom

All the oxidation numbers in H₂S

  • H +12 atoms, hydrogen
  • S −21 atom, sum rule
Questions

S in H₂S: quick answers

What is the oxidation number of S in H₂S?

S in H₂S (hydrogen sulphide) is −2.

How do you find the oxidation number of S in H₂S?

Hydrogen is +1 when bonded to non-metals. The oxidation numbers add up to the charge, 0: 2(+1) + x = 0. x = −2.

What are the oxidation numbers of the other atoms in H₂S?

H +1. Together with S at −2 they add up to the charge of the compound, 0.

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