the total entropy change of the universe is equal to the sum of the entropy change for the system plus the entropy change for the surrounding.
Every Spontaneous reaction is associated with an INCREASE IN THE ENTROPY OF THE UNIVERSE...
to find the entropy of the system at a constant temperature...use
for finding delta Ssurrounding , we have to consider the heat absorbed by the surroundings which is equal to .
At temperature T,the entropy change of the surroundings is
(at constant pressure)
Adding the two, the Entropy change for the universe can be found.
Rate if assured. Cheers!!