Yuan Tseh Lee – developer of chemical reaction dynamics

Biography & contributions

Yuan Tseh Lee was born on November 19, 1936 in Hsinchu, Taiwan

Lee is a Taiwanese chemist and Nobel laureate

Lee worked on advanced chemical kinetics techniques

In 1967 He worked on reactions between hydrogen atoms and diatomic alkali molecules

In 1967 Lee constructed universal crossed molecular beams apparatus

Awards list

1981, E.O. Lawrence Award

1983, Harrison Howe Award

1986, Peter Debye Award

1986, National Medal of Science

In 1986, he was awarded the Nobel Prize in Chemistry for his seminal contribution to the development of reaction dynamics

Chemical kinetics

It is the analysis of rates of chemical processes. Chemical kinetics includes investigations of how different experimental conditions can influence the speed of a chemical reaction and yield details about the reaction's mechanism and transition states, in addition to the construction of mathematical models that can describe the characteristics of a chemical reaction.

Physical state, concentration, temperature, pressure, catalysts, nature of elements participating in reaction could be the factors affecting chemical reactions.

Types of reactions

• Zero-order reaction
• First order reaction
• Second order reaction

Zero-order reactions

Zero-order reaction can be defined as if the rate of reaction is independent of the concentration of the reactant then the reaction is called zero order reaction.

In this type of reactions by increasing or decreasing reactants concentrations will not affect the rate of the reaction.

Zero-order reactions can be mentioned by following formula

r = k

r= reaction rate

k=reaction rate coefficient

Example

Best example for zero-order reaction is reversed Haber process

2NH_{3 (g)} → 3H_{2 (g)} + N_{2 (g)}

First order reaction

First-order reaction is a reaction that proceeds at a rate that depends on only one reactant concentration.

First-order reaction can be represented as follows

r = - d[A]/dt = d[A]

Where k= first order rate constant

Example

H₂O_{2 (l)} → H2_{O (l)} + ½ O_{2 (g)}

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