298 K पर NO एवं `O_(2)` से `NO_(2)` बनती है-
`NO(g) + 1/2O_(2)(g) ltimplies NO_(2)(g)`
अभिक्रिया के लिए `DeltaG^(@)` सीथरांक की गड़ना कीजिये-
`Delta_(f)G^(@)[NO_(2)]=52.0 ` kJ/mol
`Delta_(f)[NO]=87.0` kJ/mol
`DeltafG^(@)[O_(2)]=0` kJ/mol

Explanation

(a) `Delta_(r) G^(@) = sum Delta_(f)G^(@)` or `sumDelta_(f)G^(@)` अभिकारक
`Delta_(r ) G^(@)[NO_(2)]-[Delta_(f)G^(@)]NO+1/2Delta_(f)G^(@)[O_(2)]`
`=52.0 - (87.0 + 0) = -35kJ mol^(-1)`
(ख) `Delta_(r ) G^(@) = -2.303 RT log_(10)K_( c)`
`r=8.314 xx 10^(-3) kJ K^(-1) mol^(-1), T=298 K`
`log_(10)K_(c ) =-(Delta_(r ) G^(@))/(2.303 RT)`
`K_( c) = "antilog"(10) 6.1341 = 1.362 xx 10^(6)`