Question

Write a balanced half-reaction describing the oxidation of gaseous dihydrogen to aqueous hydrogen cations.

Answer 1

Answer:
`H_2(g\rightarrow 2H^+(aq)+2e^-`

Step-by-step explanation:

Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

`H_2(g)\rightarrow 2H^+(aq)+2e^-`

On reactant side:

Oxidation state of hydrogen = 0

On product side:

Oxidation state of
`H^+` = +1

The oxidation state of hydrogen increases from 0 to +1. Thus, it is getting oxidized and it undergoes oxidation reaction.

Answer 2

The oxidation state of hydrogen gas is 0 and oxidation state of hydrogen cation is +1.
There’s an increase in oxidation number therefore it’s an oxidation reaction.
Oxidation reactions give out electrons. The masses and charges on both sides should be balanced
Half reaction is
H2 —> 2H+ +2e