What would be the effect of increasing the volume of each of the following system at equilibrium?
a. `2CO(g) +O_(2)(g) hArr 2CO_(2)(g)`
b. `NI(s)+4CO(g) hArr NI(CO)_(4)(g)`
c. `N_(2)O_(4)(g) hArr 2NO_(2)(g)`

Explanation

Increasing volume (at constant temperature) will result in a decrease in the concentration of all the gases. As per Le- Chatelier's Principle, the reaction should move in a direction of increase in total number of gaseous moles (thereby increasing concentration). Thus, shift is in a direction of `Deltan_(g) gt 0`
(i) `2CO(g)+O_(2)(g) hArr 2CO_(2)(g) " "` [Backward direction `because (Deltan_(g)) lt 0`]
(ii) `Ni(s)+4CO(g) hArr Ni(CO)_(4)(g)" "`[Backward direction `because (Deltan_(g)) lt 0`]
(iii) `N_(2)O_(4)(g) hArr 2NO_(2)(g)" "`[Forward direction `because (Deltan_(g) gt 0`]