Question

What do you understand by redox reactions ? Explain oxidation and reduction in terms of loss or gain of electrons.

Answer 1

As the name suggests, a redox reaction is a combination of two chemical reactions- oxidation and reduction. If in a reaction oxygen/electronegative element is added to a substance or hydrogen/electropositive element is removed from a substance, we say that the substance has undergone oxidation.

$Mg\left(s\right)+C{l}_2\left(g\right)⟶MgC{l}_2\left(s\right)$

$2H_{2}S\left(g\right)+O_2\left(g\right)⟶2S\left(s\right)+2H_{2}O\left(l\right)$

When a substance undergoes reduction either oxygen/electronegative element is removed from the substance or hydrogen/electropositive element is added to the substance.

$2HgO\left(s\right)⟶2Hg\left(l\right)+O_2\left(g\right)$

$2FeC{l}_3\left(aq\right)+H_2\left(g\right)⟶2FeC{l}_2\left(aq\right)+2HCl$