To answer this question, we will first find out the number of gaseous moles on each side of the equilibrium
on the left:
we have 2 moles of A, 5 moles of B and 12 moles of C
which gives us a grand total of 19 gaseous moles
on the right:
here, we have 14 moles of AC gas, we will not count the number of moles of B because it's a solid
giving us 14 gaseous moles on the right
Where does the reaction shift?
more gaseous moles means more space taken, because gas likes to fill all the space it can
if we have more volume, more gas can move around without colliding (reacting) with each other
Hence more volume favors the side with more gaseous moles
here, the left has more gaseous moles. So we can say that the reaction will shift towards the left, or the reactants side