Rates, Equilibrium and PH Flashcards
What is the rate of a reaction?
The change in concentration of a reactant or product per unit time.
What is the order with respect to a reactant?
The power to which the concentration of a reactant is raised in the rate equation.
What is the overall order of a reaction?
The sum of the individual orders
What does it mean when a reaction is zero order?
The rate is unaffected by changing the concentration of the reactant.
What does it mean when a reaction is first order?
The rate is directly proportional to the concentration of the reactant.
What does it mean when a reaction is second order?
The change in rate will be equal to the change in concentration squared.
What is the half life of a reactant?
The time taken for the concentration of the reactant to reduce by half.
What does the concentration-time graph look like for a zero order reaction?
It will be a straight line with the concentration decreasing at a constant rate.
What does the concentration-time graph look like for a first order reaction?
It will be a curved line with a constant half life, halving the concentration at equal time periods.
What does the concentration-time graph look like for a zero order reaction?
It will be a straight line with no gradient.
What does the concentration-time graph look like for a first order reaction?
It will be a straight line through the origin.
What is a reaction mechanism?
A series of steps that together, make up the overall reaction.
What is the rate determining step of a reaction?
The slowest step in a reaction mechanism of a multi-step reaction.
What is an intermediate?
A species formed in one step of a multi-step reaction that is used up in a subsequent step and is not seen as either a reactant or a product of the overall equation.
What is a homogeneous equilibrium?
An equilibrium in which all the species making up the reactants and products are in the same physical state.
What is a heterogeneous equilibrium?
An equilibrium in which all the species making up the reactants and products are in different physical states.
What is the mole fraction of a substance?
A measure of how much of a given substance is present in a reaction mixture,
What is the partial pressure of a substance?
The pressure an individual gaseous substance would exert if occupied a whole reaction vessel on its own.
What is a Brønsted-Lowry acid?
A proton donar
What is a Brønsted-Lowry base?
a proton acceptor
What is a buffer solution?
A mixture that minimises pH changes on addition of small amounts of acid or base.
What is the equivalence point of a titration?
The point at which the volume of one solution has reached exactly with the volume of the second solution.
What is the end point of a titration?
The point on a titration curve at which there are equal concentrations of the weak acid and conjugate base forms of the indicator. The colour at the end point is midway between the colours of the acid and conjugate base forms.
