In which one of the following the increase of presure favours the backward reaction?

Options

A. Formation of equilibrium ammonia from `N_(2)(g) and H_(2)(g)`
B. Decomposition equilibrium of HI (g) to `H_(2)(g) and I_(2) (g)`
C. Synthesis of `SO_(3)` (g) by contact process
D. Production of 'syngas' by coal gasification

Answer

D

Explanation

(a) `N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g) , n_(p) lt n_(r)`
Hence, increases of pressure will favour forward reaction .
(b) `2 HI (g) hArr H_(2) (g) + I_(2), n_(p) = n_(r). `Hence , presure has no effect .
(c ) ` 2 SO_(2) (g) + O_(2) (g) hArr 2 SO_(3)(g), n_(p) ltn_(r).`
Hence , increases of pressure will favour forward reaction .
(d) `C(s)+ H_(2)O (g) hArr CO(g) + H_(2) (g) , n_(p) gt n_(r)` Hence, increase of pressure will favour backward reaction .
(e) `3Fe (s) + 4H_(2)O (g) hArr Fe_(3)O_(4) (s) + 4 H_(2) (g) , n_(p) = n_(r) . ` Hence , pressure has no erffect.