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Reaction Kinetics is the study of the rates at which chemical reactions or processes take place. One of the most advanced research in physical chemistry is being conducted at this time. Engineers and scientists can use the information about these factors affecting the rate of a chemical reaction to economically scale up the reactions to industrial size in a variety of industries, including pharmaceuticals. The rate at which a chemical reaction takes place is therefore extremely crucial for us to understand and predict.
The Influence of Temperature
The temperature of a chemical reaction is one of the characteristics that can have a significant impact on the rate of the reaction. The sight of milk boiling on a gas burner is all too common. A specific quantity of milk will boil at a different rate depending on how hot the stove is set to. When the flame height is at its highest point, the milk boils in less time, and when the flame height is at its lowest point, the milk takes longer to boil. The height of the flame corresponds to the temperature in this case.
If the temperature is high, the milk reaches its boiling point in a shorter period of time; if the temperature is low, the milk takes a longer period of time to reach its boiling point. The boiling of milk is not the only process that is influenced by the temperature of the environment. The majority of chemical reactions exhibit a change in their reaction rate as a function of temperature variation.
It has been found that for every 10 degrees Celsius increase in temperature, the rate constant for a chemical process doubles in size. It wasn’t until 1889 that someone devised a reliable physical method of measuring the temperature dependence of the rate of a chemical reaction. In 1889, Svante Arrhenius built on the work of J.H van’t Hoff and proposed an equation that quantitatively connected the temperature of a reaction to the rate constant of the reaction. The Arrhenius Equation was given to the equation that was proposed.
The Arrhenius Equation
The Arrhenius Equation, which describes the relationship between the rate of a chemical reaction and its temperature, is shown below.
Where,
The rate constant of the reaction is denoted by the letter k.
Arrhenius is represented by the letter A.
Ea = Activation with a constant value The amount of energy required for the reaction (in Joules mol1)
R is an abbreviation for Universal Gas. Constant
T is the temperature measured in absolute degrees Celsius (in kelvins)
Knowing that the rates of reaction increase with increasing temperature was common knowledge; however, how to forecast the relationship between temperature and reaction rates quantitatively was less well understood. We were able to overcome this challenge thanks to the Arrhenius Equation. It is an empirical relationship that is used to model the variation of the rate constant with temperature, which in turn provides information about the rates of chemical reactions at different temperatures. It is derived from literature.
The threshold energy is defined as
In particle physics, the threshold energy for the generation of a particle is the kinetic energy that a pair of travelling particles must have when they encounter in order to produce a particle. The threshold energy of a desired particle is always larger than or equal to the rest energy of the particle in question. For the most part, because momentum is conserved as well, the threshold energy is substantially more than the rest energy of the targeted particle, resulting in the final particles still possessing significant kinetic energy.
Contrary to the threshold energy, the threshold displacement energy is the minimum amount of energy required to permanently shift an atom in a crystal, which is the minimum amount of energy required to cause a crystal defect in the field of radiation material science.
Activation energy is defined as follows:
In chemistry and physics, activation energy is defined as the smallest amount of energy that must be provided for a compound to undergo a chemical reaction. It can be calculated as
Energy required to initiate a reaction is measured in joules per mole (J/mol), kilojoules per mole (kJ/mol), or kilopascals per mole (kcal/mol) of the reactant.
When it comes to thermodynamic states, activation energy can be defined as the magnitude of the potential barrier (also known as the energy barrier) that separates minima of the potential energy surface corresponding to the initial and final thermodynamic states. The temperature of the system should be high enough so that there is a substantial number of molecules with translational energy equal to or higher than the activation energy in order for a chemical reaction to proceed at a tolerable rate. Swedish scientist Svante Arrhenius coined the phrase “Activation Energy” in 1889, and it has been in use ever since.
The temperature dependence of the Arrhenius equation, as well as its relationship to it
When applied to reactions, the Arrhenius equation provides a mathematical basis for the link between activation energy and the rate at which the reaction proceeds. The activation energy can be calculated from the equation by using the relationship between the two variables.
where A is the pre-exponential factor for the reaction, R is the universal gas constant, T is the absolute temperature (which is commonly expressed in kelvins), and k is the reaction rate constant. The variation in reaction rate coefficients as a function of temperature, even in the absence of knowledge of A, allows one to calculate Ea (within the validity of the Arrhenius equation).
Conclusion
The amount of atomic or molecular collisions increases with temperature. Temperature affects reaction rate constants (written k) in predictable ways.
Reaction Kinetics studies the speeds of chemical reactions or processes. Now is the time for some of the most advanced physical chemistry studies. Engineers and scientists can utilize this information to economically scale up chemical reactions in a range of sectors, including pharmaceuticals. The rate of a chemical reaction is consequently vital to understand and forecast.
