Q.Differentiate irreversible and reversible reaction.

Step 1. Direction: An irreversible reaction proceeds only in one direction, indicated by a single arrow, e.g. $C(s)+O_2(g)\xrightarrow{\Delta}CO_2(g)$. A reversible reaction proceeds in both directions -- forward and backward -- indicated by a double arrow, e.g. $H_2(g)+I_2(g)\rightleftharpoons 2HI(g)$.

Step 2. Completion: An irreversible reaction continues until a reactant is completely exhausted, going to (near) 100% completion. A reversible reaction does not go to completion -- some reactants and products remain present together once equilibrium is reached.

Step 3. End state: An irreversible reaction simply stops when a reactant runs out. A reversible reaction reaches dynamic equilibrium, where forward and reverse reactions continue at exactly equal rates, so concentrations of all species stay constant even though the reaction has not literally stopped. …

Compare direction, completion, and end-state behaviour of the two reaction types, using the …

• Thinking a reaction is inherently reversible or irreversible regardless of system type -- many reactions are reversible only in a closed container. …