Redox Reactions

Redox reactions are important as they release energy.

Discussion Question:

The question that arises from seeing a simple Redox reaction such as above is that, that why 2Na reamins as 2Na while Cl₂ changes to 2Cl⁻ .


Na(Sodium) atoms do not join with each other to make a covalent or ionic bonding. However, in the start Cl₂ (Chlorine) atoms were joined together by covalent bonding with each other but as they received electrons from Sodium - each Chlorine atom separated to make an ionic bonding with each Sodium atom.


We see two half equations with -(negatives) only where is K's equation and why it has not been included in the half equations.

You may still want to answer based upon your prior discussion as to why has 2Br⁻ changed to Br₂ plus 2e⁻.


K (Potassium) remains the same in the whole process that is it just gives electron to first Br(Bromine) and then as Bromine gets displaced with Chlorine it still just gives electron to Chlorine. So that is why the half equation of K is not included as half equations mainly show movement of electrons that occur as the chemical reaction takes place.

2Br⁻ showed the first state of Br in relation to K. However, as Br gets displaced by Chlorine then 2Br⁻ gave out the electrons of K back to it and formed in itself as Br₂. "plus 2e⁻" shows that Br₂ becomes Br₂ by giving two electrons.

We can see that the redox reactions are ionic but the question arises can they be covalent as well?

In the reactions stated above why do you think why Chlorine displaces Bromine while they are in the same group of the Periodic Table.


Yes Redox reactions can be covalent as well - Redox reactions can be based upon sharing of electrons. We can be sure of this if learn from the reaction that there has been change of Oxidation states.

Chlorine displaces Bromine because Chlorine is more reactive than Bromine. They are in the same group but Chlorine has lesser shells than Bromine which makes the nucleus of the Chlorine to be more closer to other atoms to attract an electron.

Discussion Question

Cl₂ is already in bonding with Fe (after chemical reaction) then why would Fe react with more Chlorine (Cl₂) to form FeCl₃


FeCl₃ is more stable then FeCl₂. FeCl₂ formed because Chlorine never had the chance to react fully as maybe there were other atoms such Hydrogen atoms from HCL which had not let Chlorine to react fully.

Discussion Question

Explain how the Manganate ion is at oxidation level of VII

Why does Manganate ion becomes to Mn⁺²

Discussion Questions

Explain how ethanol is oxidised to ethanal.