HX (Light color) H+X (Dark color)
a) Write down the characteristics of the solution you might get points
by seeing the reaction. X is a weak acid here (2)
(b) Which theory can explain the following reaction well? 
(a) HX is a weak acid. so It's disassociation is less. So Equillibrium is takes place in between the molecules and ions.
When disassociation increases , Dark color increases.
When disassociation decreases , Light color observed.
Temperature increased dark color and decrease then light color observed.
(b) Lechatlier Principle Explains about temperature, concentration effect on equillibrium.