If the forward reaction is spontaneous will be reserve reaction also be spontaneous?

Answer 1

You may think this but its not entirely true

Because it takes a substantial amount of energy to form a product from reactants their could be less energy if the reaction was revesed because of that amount of energy to put into one side of the system.

For example:

The Combustion of C3H8 <->H20+ CO2
But it wouldn't be the same spontinuity for the reversal

Answer 2

If the reaction is a reversible reaction then both will be spontaneous (equilibrium)

If the reaction is not reversible then only one reaction will be spontaneous