General 'rule' - "like dissolves like". The solubility
of a solute in a solvent (that is, the extent of the mixing of the
solute and solvent species) depends on a balance between the natural
tendency for the solute and solvent species to mix and the tendency for a
system to have the lowest energy possible.
Hope this helps :p
Answer:
The value of 
for this reaction at 1200 K is 4.066.
Explanation:
Partial pressure of water vapor at equilibrium = 
Partial pressure of hydrogen gas at equilibrium = 
Total pressure of the system at equilibrium P = 36.3 Torr
Applying Dalton's law of partial pressure to determine the partial pressure of hydrogen gas at equilibrium:
The expression of is given by:
The value of for this reaction at 1200 K is 4.066.
Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces. So as two objects are separated from each other, the force of gravitational attraction between them also decreases.
-google
its probably 40
