Write the thermochemical equations that give the values of the standard enthalpies of formation for (a) \(\mathrm{KClO}_{3}\) (s), potassium chlorate; (b) \(\mathrm{H}_{2} \mathrm{NCH}_{2} \mathrm{COOH}\) (s), glycine(s); (c) \(\mathrm{Al}_{2} \mathrm{O}_{3}(\mathrm{~s})\), alumina.

Thermochemical equations provide a way to understand the heat changes that accompany chemical reactions. These equations are just like other chemical equations, but they also include information about the enthalpy change. Entropy change is frequently denoted by the symbol , and its unit is the joule per mole (J/mol) or kilojoule per mole (kJ/mol).

In the context of standard enthalpies of formation, thermochemical equations represent the enthalpy change when one mole of a compound is formed from its constituent elements in their standard states. For example, the equation for forming potassium chlorate () from potassium, chlorine, and oxygen, comes with an enthalpy change value that indicates the amount of energy absorbed or released during the reaction.

Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. It deals with the energy changes involved in these processes and provides a framework for understanding the energetics of reactions. For example, the standard enthalpy of formation is a concept from thermodynamics that reflects how much energy is needed to form a compound from its elements.

The principles of thermodynamics guide us in predicting whether a reaction will occur spontaneously and help us compute the balance of energy requirements for chemical transformations.

Enthalpy change, commonly referred to as , is the measure of the total heat content of a system. It is an essential concept in understanding heat transfer during a chemical reaction. This parameter can either be positive, in the case of endothermic reactions where heat is absorbed, or negative, for exothermic reactions which release heat.

For the formation of compounds such as potassium chlorate, glycine, and alumina, the values are the heat absorbed or released when these compounds are formed from their elements. This value critically influences whether a reaction is thermodynamically favorable and plays a direct role in calculating the energy balance of chemical processes.

Balancing chemical equations is a fundamental skill in chemistry that ensures the law of conservation of mass is upheld. A balanced chemical equation shows that the number of atoms of each element is the same on both sides of the equation.

When we balance thermochemical equations, we also validate that the energy aspects of the reaction are consistent. For example, having the correct stoichiometry for the reaction between potassium, chlorine, and oxygen to form potassium chlorate is crucial, as it affects the calculation of the standard enthalpy of formation. Properly balanced equations prevent discrepancies in calculations of energy changes and are vital to accurate thermochemical analysis.