Because endothermic reactions require the addition of heat as a reactant,?

Question

Than are endothermic reactions always nonspontaneous.

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Add please tell me why.

Answer 1

Sugar dissolution by example, sugar is a very stable crystalline compound, we need to add some energy, perhaps in form of heat to break the covalent bonds, that's the reason this is an endothermic reaction. It is like separating a drunkard from its bottle, a very endothermic reaction since the bonds are very, very strong, we have to sweat to tear the infamous bottle from his nasty hands.

Answer 2

For a reaction to be nonspontaneous (also known as endergonic), the expression, deltaG=deltaH - TdeltaS. In other words, delta G (the change in G) depends on three factors: the change in enthalpy (delta H), the change in entropy (delta S) and the temperature. Endothermic reactions have positive delta H, but the magnitude of entropy (randomness) can vary. Also, the temperature will vary from reaction to reaction. Therefore, I would not make the statement that all endothermic reactions are nonspontaneous (endergonic) because it depends on more than one variable, and without resting every reaction possible and calculating delta G for each, it is not possible to say.

Answer 3

Endothermic RXNs do require the input of energy. That energy must come from the surroundings. There may be a few of the molecules which react spontaneously due to the random motion of the molecules, but the entire reaction will require the input of energy.