A reaction will be nonspontaneous under all conditions when

Question

a. delta G is negative
b. delta H is negative and DS is positive
c. delta H is positive and DS is negative
d. delta H is positive independent of the value and sign of DS
e. delta S is positive independent of the value and sign of DH

?

Answer 1

dG = dH - TdS.
Go through each answer and see if it fits; for example, #1 can't be right because when dG is - the reaction is spontaneous.
#2.
If dH is - and dS is +, then the term TdS is - so dG is always - when this is true and the rxn is spontaneous. So scratch 2.
Etc.

Answer 2

e is not it.
dG = dH - TdS.
If dS is + then the term -TdS will be negative but some dH values (even though they are + values) still can give a - dG value and the reaction will be spontaneous.

Answer 3

so d then

Answer 4

no. c