Chemical Kinetics Flashcards
What is reaction kinetics?
The study of rates of reaction and factors that influence rate
What is transition state?
Highest energy on the energy curve-transient state whereby molecules can return to reactants or proceed to form products
What is kinetic profile?
How the rate of a reaction varies as reaction proceeds
What does the steepness of gradient on a rate of reaction graph tell us?
How fast the reaction is progressing
What factors affect rate of reaction?
Temperature
Concentration
Chemical nature
State of subdivisions (surface area)
Presence of catalyst
What is the ate equation of elementary reactions?
Rate=K[A]a[B]b
What types of elementary reaction are there?
Unimolecular = A—>B
Biomolecular= A+B—>C
Termolecular= A+B+C—>D
What is order of a reaction?
The power to which the convent of reactants must be raised to give a rate equation that describes the experimental data
What is differential rate equations mean?
A rate equation where the rate of consumption of a reactant/ formation of a product is written as a differential
What is the rate equation for a reaction at a particular instant during the reaction?
-d[A]= K[A]
——
dt
What is experimental data?
Measurement of the concentration of a reactant or product at different times throughout the reaction
What is the integrated rate equation of experimental data?
-In[A]t=In[A]0-Kt
What is exponential decay?
The concentration of the reactants decays as a logarithmic expand with time
What is 1st order elementary reaction?
A—> products
What is 2nd order elementary reaction?
A+A—> products
What is pseudo 1st order reactions?
A+B—> product
What is half lives?
The time taken for its concentration to fall to half of the initial value
t1/2= 0.693/K
What are the characteristics for zero order reactions?
Rate of the overall reaction is unaffected by concentration of a reactant
The half life of the reactant in a zero order reaction is proportional to the rate constant
What is the Arrhenius equation?
K=Ae*-(Ea/Rt)
What is the reaction theory of reactions?
Based on a model of how a reaction occurs at a molecular level
Collusion theory and transition state theory
What is the collusion theory?
Reactant molecules behave like hard spheres. Collusion may result in a reaction
What is the transition state theory?
Assumes the reactants form a transition state at the max on the energy profile
What is a catalyst?
Substance that changes the rate of a reaction without being consumed in the reaction
What is a heterogeneous catalyst?
Different physical state than the reactants
What is a homogeneous catalyst?
Same physical state as the reactants
