Topic F: Chemical Kinetics Flashcards
What are the conditions required for a reaction between two reactant particles to take place according to the collision theory
The particles must collide with each other
The particles must collide in the correct orientation
The particles must collide with sufficient kinetic energy that minimally meets the requirement of the activation energy
Definition of rate of reaction
The decrease in concentration of a reactant per unit time
The increase in concentration of a product per unit time
What are the main factors affecting the rate of reaction
Particle size of solid reactants
Concentration / pressure of liquid or gaseous reactants
Temperature
Presence of catalyst
What does 0, 1 and 2 order mean
0 order: Rate is independent of concentration
1 order: Rate is directly proportional to concentration
2 order: Rate is directly proportional to concentration squared
In the rate equation Rate = k[A]^m[B]^n, how can the value of m and n be determined
The value of m and n can only be determined experimentally and cannot be deduced from the stoichiometric coefficients in the chemical equations
How is the rate/concentration graph related to the concentration/time graph
The rate/concentration graph is the gradient of the concentration/time graph
What is the unit of the rate constant for a zero order reaction
mol dm^-3 s^-1
Where will a catalyst be involved in a rate mechanism
The catalyst will be involved in the slow step of the reaction
What is the difference between the intermediate and the catalyst in a rate mechanism
The intermediate will not appear in the rate equation while the catalyst will
Both will not appear in the overall chemical equation
What is the rate determining step
It is the slowest step in a multi-step reaction mechanism
It determines the overall rate of reaction and has the highest activation energy
Its rate equation represents the rate equation of the overall reaction
What factors affect the rate constant
Temperature and presence of catalyst
How can activation energy be determined from the Arrhenius Equation
The equation can be re-written in the form:
lnk = (-Ea/R) (1/T) + lnA
lnk is the y-axis
1/T is the x-axis
The gradient of the straight line will be -Ea/R, since R is a constant of 8.31, the activation energy can be calculated
