Chapter 4 Chemical Reaction Rates

This is a mind map about Chapter 4 Chemical Reaction Rate. The main content includes: reaction rate theory, influencing factors, and definition: the change in concentration of reactants or products per unit time.

Edited at 2024-10-18 20:50:40

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Chapter 4 Chemical Reaction Rates

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Outline

Chapter 4 Chemical Reaction Rates

Definition: Change in concentration of reactants or products per unit time

Influencing factors

concentration

Law of mass action: v=kc(A)^a*c(B)^b

Among them, k is the reaction rate constant, which is only related to the reaction. a b is the reaction series, obtained by calculation

Reaction order: The reaction order of a reaction is determined experimentally. The total order of the reaction = a b...

temperature

Van't Hoff's equation: for every 10°C increase in temperature, the reaction rate increases by 2 to 4 times (empirical equation)

Arrhenius equation: k=Ae^-Ea/RT

This equation can be used to calculate k at one temperature from k at another temperature

catalyst

Mechanism of action: Reduce the activation energy required for the reaction by changing the reaction process to speed up the reaction rate (cannot affect the reaction balance)

Classification

inorganic catalyst

Organocatalyst (enzyme)

It requires suitable conditions to exert its catalytic effect, but its catalytic ability is generally stronger than that of inorganic catalysts.

reaction rate theory

reaction collision theory

Definition: For a reaction to occur, the reactant particles must meet three conditions: sufficient energy, appropriate collision orientation, and the ability to collide together.

Formula: v=P*f*Z k=P*f*Z0

Among them, P is the molecular collision frequency with appropriate direction; f is the frequency of molecular collisions with sufficient energy; Z is unit time, the collision frequency of molecules A and B in unit volume. That is, the frequency of molecular collisions per unit time and unit volume Z0* c(A)*c(B)

transition state theory

Content: For a reaction to occur, the reactants must absorb energy, form an unstable transition state, and then release energy to form products.

The energy absorbed to form the transition state is called activation energy - Ea

The elementary reaction series are generally divided into first order, second order, third order and zero order.

The units of k are respectively s^-1; mol^-1*L*s^-1; mol^-2*L^2*s^-1; mol*L^-1*s^-1