QJEEM18Chf0d2: JEE Main 2018 Chemistry - Class 11 JEEM18Chf0d2 Solution: Given (i)   2Fe 2 O 3 (s) 4Fe(s) + 3O 2 (g); r G o =…

Given

(i)   2Fe₂O₃(s) $\to$ 4Fe(s) + 3O₂(g);

$\Delta$ _rG^o = + 1487.0 kJ mol^-1

(ii)   2CO(g) + O₂(g) $\to$ 2CO₂(g);

$\Delta$ _rG^o = $-$ 514.4 kJ mol^-1

Multiply reaction (ii) with 3 and we get,

(iii)   6CO(g) + 3O₂ (g)    $$\stackrel{}{⟶}$$    6CO₂(g) ;

$\Delta$ _rG^o = 3 $\times$ $-$ 514.4 = $-$ 1543.2 kJ mol ^{$-$ 1}

Now add reaction (i)   with  (iii), we get

2Fe₂O₃(s) + 6CO(g)    $$\stackrel{}{⟶}$$    4Fe(s) + 6CO₂(g)

$\therefore\,\,\,$ Free energy change of the reaction,

$\Delta$ _rG^o  =  1487.0 $-$ 1543.2  =  $-$ 56.2 kJ/mol