Numford
Oxidation number

Cu in CuSO₄

Cu is +2 in copper sulphate.

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.

Cu+2

  1. SO₄²⁻ is a known ion with charge −2.
  2. The oxidation numbers add up to the charge, 0: x + (−2) = 0.
  3. x = +2.
Rule steps

How to find it

  1. SO₄²⁻ is a known ion with charge −2.
  2. The oxidation numbers add up to the charge, 0: x + (−2) = 0.
  3. x = +2.
Every atom

All the oxidation numbers in CuSO₄

  • Cu +21 atom, sum rule
  • O −24 atoms, known ion (in SO4)
  • S +61 atom, known ion (in SO4)
Questions

Cu in CuSO₄: quick answers

What is the oxidation number of Cu in CuSO₄?

Cu in CuSO₄ (copper sulphate) is +2.

How do you find the oxidation number of Cu in CuSO₄?

SO₄²⁻ is a known ion with charge −2. The oxidation numbers add up to the charge, 0: x + (−2) = 0. x = +2.

What are the oxidation numbers of the other atoms in CuSO₄?

O −2, S +6. Together with Cu at +2 they add up to the charge of the compound, 0.

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