Discussion Forum

Amongest the chemical  reactions given below, the reactions with increasing entropy are 

(i)  $H_{2}O  \rightarrow  H_{2}O (g)$

(ii)   $C(s)+ CO_{2}(g) \rightarrow 2CO(g)$

(iii) $2H_{2}(g)+O_{2}(g)\rightarrow    2H_{2}O(l)$

(iv)   $N_{2} (g)+O_{2}(g) \rightarrow$  Mixture of $N_{2}$ and $O_{2}$

Answer:

Explanation:

(i)  $H_{2}O  \rightleftharpoons  H_{2}O (g)$  system is changed so , entropy is maximum

(ii)   $C(s)+ CO_{2}(g) \rightarrow 2CO(g)$ in  this system product has more number of gaseous moles. Thus , entropy increases

(iii) $2H_{2}(g)+O_{2}(g)\rightarrow    2H_{2}O(l)$  gasesous  system is converted into liquid system , So, entropy decreases

(iv)   $N_{2} (g)+O_{2}(g) \rightarrow$  Mixture of $N_{2}$ and $O_{2}$   mixture of $N_{2}$ and $O_{2}$  , on mixing total gaseous volume  increases in comparison to their individual volume hence entropy increases