Rate Equations (Physical) (complete) Flashcards
What effect does order of 0,1 and 2 have on the rate of a reaction?
- Zero - the reaction rate is proportional to [A]^0 (=1), so the rate is not affected by changes in [A]
- One - the reaction rate is proportional to [A]
- Two - the reaction rate is proportional to [A]^2
Define the order of reaction (with respect to a given reactant).
- The order of reaction with respect to a given reactant is the power to which concentration of the reactant is raised in the rate equation.
How do you calculate the overall order of reaction?
The sum of the powers of the concentration terms in the rate equation.
What are the uses of rate equations.
revise information about the mechanism for the reaction
What affects the value of k in a rate equation?
- Temperature (higher temp = larger k value)
What is the rate determining step in a reaction?
- the slowest step in a reaction mechanism.
Give Arrhenius equation
What does is show?
k = Ae^(-(Ea / RT))
shows the link between the rate constant, activation energy and temperature
What is the y-intercept and gradient in the natural log form of the Arrhenius equation?
Y-intercept = lnA
Gradient = -(Ea / R)
How can order of reaction be found using rate-concentration graphs?
- Zero order will have a linear line (y=a)
- First order will have a linear line from the origin
- Second order will have a curve from the origin
What is the process of an initial rates method of collecting data?
- Do several reaction starting with different concentrations. Measure the initial rate of each one.
What is the process of a continuous rates method for collecting data.
- Measure the rate at several points during one reaction.
What is Quenching of a reaction?
- Stopping a reaction, often done by adding a lot of water to dilute it, essentially freezing it in place.
