1.5 kinetics Flashcards
what is rate of reaction?
amount????? of reactant used or product produced over time
what is collision theory?
a reaction wont take place between 2 particles unless they collide in the correct orientation and with enough energy to overcome activation energy
what is activation energy?
minimum amount of energy required for particles to react.
what is a maxwell boltman distribution curve?
a graph showing the different kinetic energy of molecules in a gas.
area under maxwell boltman distrib.?
peak?
just to right of peak?
area to right of activation energy?
total number of particles
most likely energy of any single molecule
mean energy of all molecules
the particles with enough energy to react
what happens to rate when you increase the temp?
what happens to the curve?
molecules will have on average more kinetic energy and move faster so more have enough energy to over come activation energy and they’ll also collide more frequently
curve is shifted to right. lower peak as more space after activation energy but same number of molecules so total area under graph needs to be same
what happens to rate when you increase the concentration?
what happens to the curve?
particles on avergae closer together so so more frequent collisions so more chance for them to be successful
curve looks the same just higher peak
what happens to rate when you increase the pressure?
what happens to the curve?
particles on avergae closer together so so more frequent collisions so more chance for them to be successful
curve looks the same just higher peak
why does the maxwell boltman distribution curve start at the origin?
because no particles have no energy
what is a catalyst?
a substance that increases the ror by providing an alternative pathway with lower activation energy. it remains chemically unchanged at the end of the reaction and is not used up (so only need a little bit). diff catalyst for diff reaction
what is an example of using catalysts in industrial processes
page 117
how does a catalyst change the maxwell boltman curve?
particles still have same amount of energy but more have enough energy to overcome activation energy and react. the line for where activation energy is just shifts left
rate of reaction =
what are the units?
amount of reactant used or product formed / time
units change eg g/s or cm^3/s
ways to measure ror?
time taken for precipitate to form (see when x disappears)
change in mass (do reaction on mass balance)
gas volume (collect gas in gas syringe)
practicals in this topic
measuring rates of reaction
