Are endothermic reactions always nonspontaneous

Answer 1

No, many exothermic reactions need the heat of activation to start the reaction. Paper, for instance, does not spontaneously burst into flame... you need to raise its temperature to the kindling point for it to burn.

Answer 2

All reactions need some activation energy. With a endothermic reaction it is absorbing energy from its surroundings. So endothermic reactions can be spontaneous if there is sufficient energy in its surrounding but if there is not then it will never happen. To answer your question endothermic reactions are always nospontanius.

Answer 3

No, but usually they are because an exergonic reaction means ∆G is negative, usually indicating that ∆S (the entropy, or disorder) is very high. Spontaneous reactions run in the direction that creates the most disorder.

Answer 4

Chemical reactions are only spontaneous when ∆Gº is negative. An since ∆Gº = ∆Hº - T∆Sº, ∆G will always be negative if ∆H is negative and ∆S is positive.

Answer 5

Yes. An exergonic reaction is a reaction with a negative change in Gibbs Free Energy. By definition, this is a spontaneous reaction.

Answer 6

One example is to put your hand accidentally on a very hot plate - the response to withdraw your hand is very spontaneous.

Answer 7

No, endothermic reactions can be spontaneous if the entropy change is favorable enough to drive the reaction forward. The spontaneity of a reaction depends on both the enthalpy and entropy changes.

Answer 8

yes.

Answer 9

no