Rotten bananas, apples or rusted utensils, using aluminum in a microwave and it sparks like it’s going to explode. These are all chemical reactions.
Enthalpy reference to the decrease or increase in energy that takes places during a chemical reaction. Each molecule present has an amount of chemical energy which is stored in between what connects the atoms. Higher the energy in the chemicals, lesser the stability in them. This in return makes them more likely to react.
An exothermic reaction is when the chemical start with a high energy and end up with lesser energy, for example when hydrogen and oxygen molecule combine together to form water.
An endothermic reaction is when the final result in terms of energy is more than when it started. For example – when baking a cake, adding heat from the oven causes a change in the chemical structures if proteins found in the eggs and the other materials in the butter.
These processes result in what we call Enthalpy
Entropy: the reactions caused by independent factors. The shift in entropy causes an instability which aids in reactions to happen. The actual chemicals when shift from their structure makes them react. Entropy helps the reaction.
An example of both enthalpy and entropy occurring would be that of a camp fire – when you light a match to burn the firewood, the match aids in adding energy by using the exothermic reaction of combustion. This combustion takes place when the high energy material present in the wood get converted to a lower form of energy in carbon dioxide and water. Now when the wood burns get converted into freely moving water vapors and carbon dioxide, this is the cause of entropy. The energy that gets made by this exothermic reaction aid in the cooking of the smores with the help of the endothermic reaction.