Observation and intuition are ladder of progression in Science. When in a garden we see plants dying, what will be the first thing coming to mind:
A: Lack of water or hot climate
B: Disproportion of minerals in soil and their rate of absorption by the vascular bundles of plant.
For sure, it will be option ‘A’ as we all understand this phenomenon more easily and it stated in a language, which is simple to interpret and relate. It is human behavior to adopt for ways which are effortless to explain and more feasible. This behavior is Occam razor theory.
Occam razor theory states that if same fact has two theories select the simplest one. A simple explanation of a fact is more accurate and require fewer assumptions. The theory is used in Science to distinguish the hypothesis by arguments. If an observation is stated with multiple hypothesis then the one, which has simple explanation of relationship, is considered more accurate to be tested. Also, when a scientific argument is written or said in an influential way it gains more acceptance because it is understood and well related to common people.
The theory plays an important role in explaining the concepts of chemistry. The chemical reaction occur at atomic level involving multiple changes, which cannot be observed. Therefore, collision theory is used to explain such changes in a simple and adoptable language. The collision theory states that reaction occurs when particles collide with sufficient energy in correct orientation. This theory is easy to visualize and therefore easy to interpret. Same problem encounter in explaining the reaction mechanism, but as humans look for pattern and harmony the representation of a complicated mechanism involves the law of harmonics with least change in atomic position and electronic configuration. The logical construction of mechanism is based on limited experimental facts and the general law of harmonics applies to specific law of mechanisms.
In order to make things simple scientist use Occam razor theory and make assumptions. The assumptions the mainly not because the effects do not occur but because the impact of the effect is negligible. For instance while calculating equilibrium constant of a monoprotic acid if the concentration of dissociated ion is low it is ignored in the denominator during calculation
Kc = [H+][A-]/HA-[α] if α too small then [HA] Kc = [H+][A-]/HA
Similarly, in energetics during the experiment we assume that there is no loss of heat to surrounding though we know that there is no system which completely insulates, also for ionic aqueous solution the density of water is considered and the ion density is ignored. It is not that these values do impact the results but the effect is considerably low and unavoidable.
While studying acid base the pH scale is used to represent [H+], this is done to understand larger number in simple logarithm form and helps in easy comparison as number between 1 to 14 are easy to visualize.
Thus, Occam razor theory governs the methodical principles in chemistry and helps in making predictions by assuming certain factor to be constant or ignored if the effect is negligible.