Chapter 1 Flashcards
(27 cards)
What are chemical kinetics?
The investigation of reaction rates and the factors that affect them
what is the formula for rate?
change in quantity/ change in time
What are the 8 ways of measuring rate?
Mass (solid), Mass (gas), Volume, concentration, pH, Colour, pressure, conductivity
How do you measure the change in mass?
a balance, g/min
How do you measure change in volume (gas)?
eudiometer, mL/min
how do you measure the concentration of an aqueous solution?
a buret, M/min
How do you measure pH?
pH paper, or litmus paper, M/min
how do you measure colour?
a spectrophotometer, %/min
How do you measure pressure (gas)?
a manometer, kPa/time
How do you measure conductivity of an aqueous solution?
conductivity meter, /s
What are the 5 factors that affect rate of reaction (number of collisions)?
- temperature (^temp=KE=^speed=^rate)
- pressure (^pressure=less volume=^rate)
- Concentration (^conc=^rate)
- Surface area (^SA=^rate)
- Phase (aq>g/l>s)
What is a catalyst?
increases the rate by providing an alternate reaction mechanism with a lower activation energy
What is an inhibitor?
decreases the rate by providing an alternate reaction mechanism with a lower activation energy
How do you calculate the # of possible collisions between A & B?
A x #B = total possible collisions between A & B
What does collision theory state?
reaction rate depends on:
- # of collisions per unit of time
- fraction of collisions that succeed in producing products
What is activation energy?
The minimum KE that the reacting species must have in order to react
How does temperature affect the number of effective collisions?
^temp=^#of effective collions
What two things must happen for a successful collision to occur?
- enough KE
- favourable geometry
What is enthalpy?
the potential energy that may be given off or absorbed as heat
What is bond energy?
The chemical potential energy able to break a bond
What are the four characteristics of activated complex?
- high energy
- in-between
- unstable
- short lived
What are elementary processes?
The individual steps in a series
What is reaction mechanism?
series of steps added together to give an overall chemical reaction
What is the rate determining step?
limits the overall reaction rate, slowest step, highest activation energy
