09 - rates of reaction

Question 1

reaction kinetics

Answer 1

the study of rate of chemical reaction

Question 2

rate of reaction

Answer 2

the change in the amount or concentration of a particular reactant or product per unit time,

mol dm-3

Question 3

rate of reaction equation

Answer 3

rate = change in amount of reactants or products / time

Question 4

methods for following the course of a reaction

Answer 4

1. SAMPLING
   taking samples or reaction mixture at regular time intervals and carrying out a chemical analysis on each sample
2. CONTINUOUS
   physical property of the reaction mixture monitored over a period of time (eg colorimetry, gas volume change)

Question 5

rate of reaction in a graph

Answer 5

. y axis is concentration
. x axis is time
. gradient = rate of reaction

Question 6

collision theory

Answer 6

in order for particles to react when they collide, they must have sufficient energy and collide in the correct orientation

Question 7

ineffective collision

Answer 7

. particles collide without sufficient kinetic energy
. collisions can be ineffective because reactive parts of the molecules aren’t close enough to each other

Question 8

effective collision

Answer 8

. collisions of particles which lead to bond breaking and a chemical reaction

Question 9

activation energy

Answer 9

the minimum energy required for colliding particles to possess for a collision to be effective

Question 10

catalyst

Answer 10

substance that increases the rate of reaction without being chemically changed itself

Question 11

more rate of reaction

Answer 11

. more frequency of collisions
. more proportion of particles with energy greater than the activation energy

Question 12

more concentration

Answer 12

more frequency of collsions, more rate of reaction

Question 13

boltzmann distribution

Answer 13

. y axis is number of molecules
. x axis is molecular energy
. area under graph is number of molecules
. area after Ea is nom molecules with energy more than activation energy

Question 14

boltzann : more temp

Answer 14

. longer graph
. shorter highest point
. highest point is further down x axis

Question 15

boltzmann : catalyst

Answer 15

. same
. Ea behind
. more area after Ea

Question 16

catalysis

Answer 16

how increase in rate of a chemical reaction brought about by addition of particular substances which aren’t used up in the reaction

Question 17

homogeneous

Answer 17

when both reactants and catalyst in a catalysed reaction are in the same phase

Question 18

heterogeneous

Answer 18

when both reactants and catalyst in a catalysed reaction are not in the same phase