Which of these reaction has `DeltaS^(@)gt0`?

Which of the following reaction has Delta H = Delta U ?

For which of the following reactions, DeltaS gt 0 -

Which reaction has a positive DeltaS_(reaction)^(@)?

Which of the following set has Delta_fH°=0 ?

Which of the following set has Delta_fH°=0 ?

A reaction has DeltaH^(@) gt0 and DeltaG^(@) gt0 25^(@)C . This reaction:

What is meant by free energy of a system ? What will be the direction of the chemical reaction when (i) Delta G = 0 (ii) Delta G gt 0 (iii) Delta G lt 0 ?

Which reaction has the lowest Delta G^(underset(+)overset(+)"") or (Activation-Energy)?