Question

what should be the entropy (+ or - ) to decide wheater its a spontaneous reaction or not?

Answer 1

If the entropy of the system is positive (+), then the system becomes more disordered through the course of the reaction.
If it is negative (-), the system becomes less disordered (or more ordered) through the course of the reaction which means spontaneous!

Answer 2

Explanation:

I hope it may help to you..