chemistry - unit 2.3 Flashcards
What does the rate of a chemical reaction normally depend on?
The concentrations of the reactants.
What are orders of a reaction used for?
To relate the rate of a reaction to the reacting species.
If changing the concentration of a reactant A has no effect on the rate of the reaction, what is the reaction with respect to A?
Zero order.
If doubling the concentration of a reactant A doubles the rate of the reaction, what is the reaction with respect to A?
First order.
If doubling the concentration of a reactant A increases the rate of the reaction fourfold, what is the reaction with respect to A?
Second order.
What is the order of a reaction with respect to any one reactant?
The power to which the concentration of that reactant is raised in the rate equation.
What is the overall order of a reaction?
The sum of all the powers to which the concentrations of the reactants are raised in the rate equation.
How can the order of a reaction be determined from?
Only from experimental data.
What can the rate equation and the rate constant, including units, be determined from?
Initial rate data for a series of reactions in which the initial concentrations of reactants are varied. These can be zero, first, second or third order.
How do reactions usually occur?
By a series of steps called a reaction mechanism.
What is the rate of reaction dependent on?
The slowest step, which is called the ‘rate determining step’.
What can be used to determine possible reaction mechanisms?
Experimentally determined rate equations.
