Question

What are the reduced components in this reaction? $ {\text{Zn }} + {\text{ 2H }} \to {\text{ Z}}{{\text{n}}^{2 + }}{\text{ }} + $ .

Answer 1

Hint: When a reactant loses electrons during a reaction, it is called oxidation. When a reactant gains electrons during a reaction, it is called reduction. When metals react with acid, this is a common occurrence.

Complete step by step answer:
Since, we know that zinc metal is reacting with a quantity aqueous solution, this reaction is termed as a redox reaction where oxidation and reduction takes place simultaneously.
Let’s understand how the reaction will work and why this reaction is termed as redox reaction.
Despite the fact that the two reactions occur simultaneously, writing the oxidation and reduction reactions separately as half reactions may be beneficial. Only the oxidised or reduced reactant, the corresponding product species, any other species needed to balance the half reaction, and the electrons transferred are included in half reactions. Loss of electrons is written as a product, while gain of electrons is written as a reactant. For eg, in our previous equation, we've removed the chloride ions.
 $ Zn(s) + 2{H^ + }(aq) \to Z{n^{2 + }}(aq) + {H_2}(g) $
Atoms of zinc are oxidised to $ Z{n^{2 + }} $ . The half reaction for the oxidation reaction, is as follows:
 $ Zn \to Z{n^{2 + }} + 2{e^ - } $
This half reaction is balanced in terms of the number of zinc atoms involved, and it also depicts the two electrons needed as products to account for the zinc atom losing two negative charges to become a $ 2 + $ ion. There's one more thing to balance in half reactions: the total charge on either side of the reaction. If you look at either side of this reaction, you'll notice that they both have a net charge of zero.
In this reaction, hydrogen is reduced. The half-reaction of balanced reduction is as follows:
 $ 2{H^ + } + 2{e^ - } \to {H_2} $
On either side, there are two hydrogen atoms, and the two electrons written as reactants help to neutralise the reactant hydrogen ions' $ 2 + $ charge. Again, all sides have a zero net fee.
The total reaction is actually the sum of the two half reactions, and can be seen by adding them up.

$ \ Zn \to Z{n^{2 + }} + 2{e^ - } \\ 2{H^ + } + 2{e^ - } \to {H_2} \\ \ $

$ Zn + 2{H^ + } \to Z{n^{2 + }} + {H_2} $

So, the reduced component in the reaction is $ {H_2} $

Note:
Redox reactions are often balanced by first balancing each half reaction separately, then combining the two balanced halves. For all of the electrons to cancel in a half reaction, all of the coefficients must be multiplied by an integer.