Thermochemistry is the Application of the First Law of Thermodynamics
Thermochemistry is the application of the first law of thermodynamics to chemical events that discuss the heat that accompanies chemical reactions.
Thermochemistry can be defined as a part of chemistry that studies the dynamics or changes in chemical reactions by observing only the heat / thermals. One of the applications of this knowledge in daily life is the chemical reaction in our body where the production of the energies needed or expended for all the tasks we do. Combustion from fuels such as oil and coal are used for electricity generation.
Gasoline that is burned in a car's engine will produce power that causes the car to run. If we have a gas stove it means we burn methane gas (the main component of natural gas) which produces heat for cooking. And through a sequence of reactions called metabolism, the food eaten will produce the energy we need for the body to function. Almost all chemical reactions there is always energy taken or expelled.
With studies conducted on the application of thermochemistry in everyday life. And to outline the problem in more detail, the author tries to make a paper whose contents discuss the "Application of Thermochemistry in Everyday Life".
Thermochemical Equations
Is a reaction equation that includes the enthalal change (DH).
The DH value written in the thermochemical equation, adjusted for the stoichiometry of the reaction, means = the number of moles of a substance involved in a chemical reaction = the reaction coefficient; (the reactant phase and the reaction product must be written).
Problems example :
In the formation of 1 mole of water from hydrogen gas with oxygen at 298 K, 1 atmosphere is released at 285.5 kJ.
The thermochemical equation:
If the coefficient is multiplied by 2, then the price of the reaction DH must also be multiplied by 2.
Some things that must be considered in writing the thermochemical equation:
The reaction coefficient shows the number of moles of the substance involved in the reaction.
When the reaction equation is reversed (changing the reactant's location with the product), the DH value remains the same but the sign is opposite.
If we multiply both sides of the thermochemical equation by the y factor, the DH value must also be multiplied by the y factor.
When writing the thermochemical reaction equation, the reactant phase and the product must be written down.
Energy Changes in Chemical Reactions
Almost in every chemical reaction there will always be absorption and release of energy. If chemical changes occur in the bulkhead container, so there is no heat entering or leaving the system. Thus the total energy possessed by the system is fixed. There are two energy changes in a chemical reaction: endothermic changes and exothermic changes. Endorterm changes are changes that are able to flow heat from the system to the environment or release heat into the environment
When exothermic changes occur as the temperature of the system increases, the potential energy of the substances involved in the reaction decreases. While the exothermic change is the heat that will flow into the system. If an endothermic change occurs, the temperature of the system decreases, the potential energy of the substances involved in the reaction will increase.