What is the relationship between enthalpy and temperature?

Answer 1

Enthalpy is the amount of energy in a system and when this changes (when a reaction happens), the energy is either released (exothermic) or absorbed (endothermic) and this energy is usually released or absorbed as heat. Therefore when the enthalpy decreases, heat is released from the system making it exothermic. In contrast, when the enthalpy increases, heat is absorbed making it endothermic.

Answer 2

Enthalpy of water (100% liquid, 0% steam) has a direct relation with pressure and temperature

Enthalpy of vaporisation (mixture of liquid and steam) has an inverse relation with pressure and temperature

Enthalpy of steam (100% steam, 0% liquid) at saturation has a direct relation with pressure and temperature

Enthalpy of super-heated steam (steam at a temperature above its saturation temperature) has a direct relation with temperature and an inverse relation with pressure

Answer 3

enthalpy is a diffrence of reducing temperature. and temperature is a hotness or coldness of a product or a area.

The above answer can be re-state as:

Enthalpy is a measure of the total energy inside a thermodynamic system. (emphasize on thermodynamic because enthalpy and temperature in classical way are not defined beyond chemical equilibrium). There are actually two types of enthalpy but people don't usually make a difference: formation enthalpy and sensbile enthalpy. Sensible enthalpy is the one related to temperature. Sensible enthalpy is the energy change in the system as the temperature of the system is modified. Mathematically is expressed in terms of specific heat at p=const and temperature i.e.: h=cp*T (for calorically perfect gas only). The formation enthalpy is a different story has to do with the chemical energy of the molecule (sometimes this is also called heat of formation). Hope this helps!