Entropy is the degree of disorderliness or randomness of a system. It is the measure of the unavailable energy in a system.
Entropy increases with increase in the number of particles. If the number of particles in a system increases from left to right, the entropy of the system increases accordingly.
In reaction 1, the number of particles from left to right increased from two to three hence the entropy was increased.
In reaction 2, the number of particles from left to right increased from three to five hence the entropy was increased.
