rate of reaction

week 4, question 2 + 4

A reaction between two particles can only occur if the particles collide with

sufficient energy and correct orientation

activation energy

minimum energy needed for a collision to be successful

increasing temp on rate

• more kinetic energy = more frequent collisions

• more energy > Ea = more successful collisions

• increased rate

increasing conc on rate

• more particles in a unit volume

• more FREQUENT SUCCESSFUL collisions

• increased rate

increasing pressure on rate

• particles are pushed closer together

• more FREQUENT SUCCESSFUL collisions

• increased rate

increasing SA of solid on rate

• more particles on the surface are exposed + available

• for FREQUENT SUCCESSFUL collisions

• increased rate

adding a catalyst on rate

• alt pathway with lower Ea provided

• increased rate

rate =

[conc] / time

rate units

mol dm^-3

steeper line

faster reaction

zero order rate-conc graph

horizontal line

first order rate-conc graph

directly proportional

second order rate-conc graph

curve

what affects the value of K

temp and catalyst

rate equation

rate = k [A]ⁿ [B]^m

overall order =

sum of the powers

when does initial rate start

t = 0

zero order

first order

second order

half life

the amount of time needed for a reactant concentration to decrease by half

first order and half life

constant half life