A reaction is always non-spontaneous when

Question

a. ∆H>0, ∆S>0
b. ∆H>0, ∆S<0
c. ∆H<0, ∆S<0
d. ∆H<0, ∆S>0

Gibb's Free Energy is
a. the difference between the activation energy and reaction enthalpy
b. the difference between the enthalpy of the reactants and products
c. the sum of the enthalpy and entropy
d. the usable energy leftover in a reaction

Answer 1

always non-spontaneous when dS<0 and dH>0. Looks like b.Do you understand why?
dG = dH - TdS.
For spontaneity dG must be -. So when
dH is >0 it is +; when dS <0 is is - and -TdS is +. + added to + is + and when dG is + the reaction doesn't go anywhere by itself.
Next question. dG = dH - TdS
d is the answer. G is the amount of usable work.