kinetics Flashcards
equation used to calc rate
change in conc/time
unit for RoR
mol dm-3 s-1
what must particles have to react
sufficient activation energy and correct orientation
do most collisions result in a reaction
no
factors affecting RoR
temp
pressure
conc
surface area
surface are
catalyst
effect of increasing temp
increase RoR
higher proportion of particles have sufficient activation energy therefore many more frequent successful collisions per second therefore increasing rate
effect of increasing conc/pressure on RoR
increase RoR
there are more particles in a given volume therefore more frequent successful collisions therefore increased rate
variables in an experiment that can be monitored to calc RoR
conc of reactant or product
gas volume of products
mass of substances formed
how to calc rate from a conc time graph
draw a tangent
work out gradient using change in y-change in x
what is a catalyst
a substance which increases the RoR but is not used up in reaction
how do catalysts work and how do they increase RoR
provide alternate reaction pathway with a lower activation energy
due to however activation energy, more particles have sufficient activation energy so more frequent successful collisions so increased reaction rate
what does homogeneous catalyst mean
a catalyst that is in the same phase as the reactants e.g liquid catalyst mixed with liquid reactants
heterogeneous catalyst
catalyst is in a different phase to the reactants
e.g solid catalyst with gas reactants
heterogeneous catalyst
catalyst is in a different phase to the reactants
e.g solid catalyst with gas reactants
economic benefits of the use of catalysts in industrial reactions
reactions occur at lower T so less fuel required, therefore few fossil fuel emissions
alternative process with higher atom economy so fewer raw materials are needed and less waste products are produced
