Question

Which one of the following is a redox reaction?. 2 Na(g) + Cl2(g) 2 NaCl(s) A. K2Cr2O7(aq) + 2 KOH(aq) 2 K2CrO4(aq) + H2O(l) B. H2O(l) H+(aq) + OH -(aq) C. Na2CO3(s) + 2 HCl(aq) 2 NaCl(aq) + CO2(g) + H2O(l) D. Ba2+(aq) + SO42-(aq) BaSO4(s)

Answer 1

2Na(g) + Cl2(g)  2NaCl(s) is the redox reaction. Na atoms lose electrons and Cl atoms gain electrons, thereby getting oxidized and reduced respectively and fulfilling the requirement of a redox reaction.

Answer 2

Answer: Option (a) is the correct answer.

Explanation:

A redox reaction is defined as a reaction in which there occurs a change in oxidation state of the reacting species.

For example, $2Na(g) + Cl_{2}(g) \rightarrow 2NaCl(s)$

Here, oxidation state of sodium is changing from 0 to +1 and oxidation state of chlorine is changing from 0 to -1.

Therefore, this change in oxidation state of the reactants depicts a redox reaction has occurred.

Thus, we can conclude that out of the given options $2Na(g) + Cl_{2}(g) \rightarrow 2NaCl(s)$ is a redox reaction.