Chapter 18 Flashcards
Rates of Reaction (11 cards)
What is the rate of a reaction?
The change in concentration of a reactant or product divided by the time taken for that change
What is the order of a reagent in a reaction?
The order of a reagent is the power to which the concentration of the reagent is raised in the rate equation for the reaction. It tells us how rate is affected by changing the concentration of a reactant.
What is the overall order?
The sum of the individual orders of the reagents in a reaction
What is the rate constant?
the constant of proportionality (k)
What is the half life of a reaction?
the time taken for the concentration of a reactant to fall to half of its original value
Which shape of a rate concentration graph would you expect a 0 order reagent to have?
Straight line. Rate is not affected by concentration
Which shape of a rate concentration graph would you expect a 1st Order to have?
starts from origin, straight line diagonally up
Which shape of a rate concentration graph would you expect a 2nd Order reagent to have?
change to rate starts slow and increases exponentially
Which shape of a concentration time graph would you expect a 0 order reagent to have?
concentration starts off high and decreases linearly as time progresses
With what equation would you measure the rate constant (k) from a half life
ln( 2) / half life
half life = t1/2
WHat is meant by the rate determining step?
The slowest steo in the mechanism. The overall rate of reaction is decided by this slow step
