Question

In the reaction, $$Fe+2HCl\to FeC{l}_2+H_2$$. What is the oxidation state of $$Fe$$ in $$FeC{l}_2$$?
A. $$+2$$
B. $$+3$$
C. $$+4$$
D. $$+5$$

Answer 1

Hint: We need to know that the iron is the chemical element having the atomic number $$26$$. The iron is a metal which belongs to the first transition series. The belonging group and period are eight and four respectively. The hydrochloric acid is a strong acid having the formula, $HCl$. The elements present in the compound are hydrogen and chlorine. The ferrous chloride is also known as iron (II) chloride which is a chemical compound with formula, $$FeC{l}_2$$.

Complete answer:
The given chemical reaction undergoes both oxidation and reduction reaction. Hence, it is a redox reaction. In this reaction, $$Fe+2HCl\to FeC{l}_2+H_2$$, hydrochloric acid acts as the oxidizing agent and iron acts as a reducing agent.
The oxidation – reduction can be written as,
$$2H^I+2e^{-}\to 2H^0\left(Oxidation\right)$$
$$F{e}^0-2e^{-}\to F{e}^{II}\left(\mathrm{Re}duction\right)$$
The oxidation state of chloride ions in ferrous chloride is $$-1$$. Let ‘X’ be the oxidation state of iron in $$FeC{l}_2$$. Hence, the oxidation state of iron in $$FeC{l}_2$$ can be found out by substituting the value of oxidation state of chloride ion in $$FeC{l}_2$$.
$$X+2\left(-1\right)=0$$
$X-2=0$
$\Rightarrow X=0$
Therefore, the oxidation state of iron in $$FeC{l}_2$$ is equal to $$+2$$. Hence, option (A) is correct.
The oxidation state of ferrous chloride will not equal $$+3$$. Hence, the option (B) is incorrect.
The oxidation state of $Fe$ in $$FeC{l}_2$$ is not equal to $$+4$$. Hence, the option (C) is incorrect.
By substituting the oxidation state of chloride in $$FeC{l}_2$$, the oxidation state of iron will not get as $$+5$$. Hence, the option (D) is incorrect.

So, the correct answer is “Option A”.

Note:
As we know, the oxidation – reduction reaction is also known as redox reaction. This is a type of chemical reaction that undergoes the transfer of electrons between two species. During a chemical reaction, the oxidation state of an atom, molecule or ion may change. It may increase or decrease the oxidation number by losing or gaining the electrons.