NCERT Class XI Chemistry Equilibrium Solutions

© examsnet.com
Question : 24
Total: 73
Calculate (a) ΔG° and (b) the equilibrium constant for the formation of NO2 from NO and O2 at 298 K
NO(g)+
1
2
O2(g)
NO2(g)
where ΔfG°(NO2) = 52.0 kJ/mol, ΔfG°(NO) = 87.0 kJ/mol, ΔfG°(O2) = 0 kJ/mol
Solution:  
(a) ΔG° = ΣΔfG° (Products) − ΣΔfG° (Reactants)
= ΔfG°(NO2)[ΔfG°(NO)+
1
2
Δf
G°
(O2)
]
= 52.0 - (87.0+
1
2
×0
)
= - 35.0 kJmol1
(b) –ΔG° = 2.303 RT log K
Hence, –(–35000) = 2.303 × 8.314 × 298 × log K
or log K = 6.1341 or K = antilog (6.1341) or K = 1.361 × 106
© examsnet.com
Go to Question: