Question

Some chemical reactants are listed in the table below. Complete the table by filling in the oxidation state of the highlighted atom. species oxidation state of highlighted atom H,O*(aq) CHCI;(1) Cu (s) Br (9) x 5 ?

Answer 1

Answer - Find Oxidation states for the highlighted elements,

For H₃O⁺ (aq)

We know that,

Oxidation State of H = +1

So,

3 * Oxiadation State of H + oxidation state of O = +1

So, Oxidation State of O = +1 - (3*1)

Oxidation State of O in H₃O⁺= -2

For CHCl₃ (l)

We know that,

Oxidation State of H = +1 and of Cl = -1

So,

Oxidation state of C + oxidation state of H + (3 * oxidation state of Cl) = 0

So, Oxidation state of C in CHCl₃ = 0 - (1) - (3 *-1)

Oxidation state of C in CHCl₃ = +2

For Cu₂O (s)

We know that,

Oxidation State of O = -2

So,

2 * Oxidation state of Cu + oxidation state of O = 0

So, 2 * Oxidation state of Cu [Cu₂]in Cu₂O = 0 - (-2)

Oxidation state of Cu₂ in Cu₂O = +2 [Answer]

It is confusing as the highlighted element is Cu₂ not Cu.

But if is misprint then the oxidation state of Cu in Cu₂O is +1. [Answer]

For Br₂ (g)

We know that, oxidation number in elemental state of any element is ZERO.

So, Oxidation State of Br in Br₂ is 0. [Answer]