Signs for enthalpy

[Riya Sood 4G]

Are enthalpies always expressed as positive? Can they ever be negative?

[Eesha Sohail 1D]

Negative enthalpy would indicate that through a reaction, heat was lost. A reaction with negative enthalpy is the same as an exothermic reaction.

[Alison Trinh 1E]

Positive enthalpies are equivalent to endothermic reactions that take up heat. Enthalpies can be expressed as negative when a reaction is exothermic and therefore releases heat and warms the surroundings.

[Jacob Motawakel]

Enthalpies can be negative, indicating an exothermic reaction.

[Emily Burghart 1k]

When a reaction has a negative enthalpy, it is considered ectothermic because it is releasing heat. You can think of how ecto sounds slightly like exit, and the negative sign as subtracting heat from a system and sending it into its surrounding environment. For endothermic, think of endo like enter. Endothermic enthalpies are positive because the heat must be entered, or added into a system. Heat is thus taken from its environment.

[Hannah Romeo 1J]

Enthalpy means the amount of heat transferred. In an exothermic reaction heat is released, therefore the enthalpy is negative. It is the reverse for an endothermic reaction.

[sarahforman_Dis2I]

Since enthalpy is a measure of the heat released or gained in chemical reactions, it can be negative. If a reaction has a negative enthalpy, that means it is losing enthalpy to the surroundings (releasing heat), meaning it is exothermic

[805097738]

the sign of enthalpy indicates if the reaction is endothermic (positive) or exothermic (negative)

[pmokh14B]

Enthalpy is positive for endothermic reactions or indicates energy needs to be put in (i.e breaking bonds). negative enthalpy indicates exothermic reactions, or breaking bonds.