Kinetics

Question 1

What is the difference between kinetics and thermodynamics?

Answer 1

kinetics - tells us how fast a reaction occurs

thermodynamics - tell us if a reaction will happen and by how much

Question 2

What is the difference between rate for reactants and products?

Answer 2

reactants
- negative x change in concentration of reactants over change in time
products
- positive x change in concentration of products over change in time

multiply by 1/stoichiometry

Question 3

What is the difference between differential and integrated rate laws?

Answer 3

differential - shows how rate changes over time

integrated - shows exact concentration at a specific time, requires initial concentration

Question 4

What are the two forms of the first integrated rate law?

Answer 4

integral rate law
exponential decay

first integral rate law can be multiplied with exponential to get exponential decay

Question 5

Why are there two forms for the first integrated rate law?

Answer 5

reactants in first order processes decay exponentially with time
- the more reactants, the greater the decay

Question 6

What does the graphical representation of the integrated first, second and zero orders show?

Answer 6

first and zero orders
time on the x-axis 
ln [A] on the y-axis 
ln [A]0 as the y-intercept 
straight line going down - negative graph 

second order 
time on the x-axis 
1/ln [A] on the y-axis 
1/ln [A]0 as the y-intercept 
straight line going up - positive graph

Question 7

What is half-life?

Answer 7

t1/2

- time taken for a substances quantity to fall to half that which was initially measured

Question 8

What is the half life for a first order reaction?

Answer 8

half life of a first order reaction is independent of the initial concentration

Question 9

What is accelerated stability testing?

Answer 9

testing at a range of higher temperatures under controlled conditions
- used to predict rate at which drugs degrade at room temperature