11A.5

Question 1

what is activation energy

Answer 1

the minimum energy colliding particles must possess for the reaction to occur

Question 2

once enough activation energy is there to reach the transition state the particles can

Answer 2

the particles can form products and release energy as they do so

Question 3

where is the transition state in at energy profile diagram

Answer 3

it is at the peak of the curve (page 19)

Question 4

what are the two groups of catalysts

Answer 4

1. homogenous catalysts
2. heterogeneous catalysts

Question 5

what is a homogenous catalyst

Answer 5

it is a catalyst that is in the same phase as the reactants

Question 6

why are CFCs bad

Answer 6

there are chlorofluoro carbons and they are responsible for the destruction of the ozone layer

Question 7

what are examples of homogeneous catalysts

Answer 7

1. reaction between chlorine free radicals from CFCs (caused by ultraviolet light) and Oxone layer
2. peroxydisulfate and either iron 3+ or 2 +

Question 8

more information about peroxydusulfate and iron

Answer 8

page 20

Question 9

what is a heterogeneous catalyst

Answer 9

it is a catalyst that is in the diff state as the reactant

Question 10

what are Interstitial hydrides

Answer 10

hydrogen bonds with transition metals.

Question 11

what are two examples of heterogeneous catalysts

Answer 11

1. iron for Haber process
2. vanaduim(v) oxide for the Contact process

Question 12

how does the iron catalyst speed up the Haber process

Answer 12

Iron forms interstitial hydrides with the hydrogen molecule at which the hydrogen atoms re held in place between the metal ions in the lattice the nitrogen molecules are then absorbed into the metal surface nearby where they react with iron and then ammonia is desorbed from the iron

Question 13

what is adsorption

Answer 13

the adhesion of ions, molecules, or atoms to a surface of a solid

Question 14

what are the three stages in catalysis involving surface absorption (like the Haber process)

Answer 14

1. adsorption: the reactants are adsorbed into the surface of the metal
2. reaction: the reactant molecules are held in positions that enable them to react together
3. desorption: the product molecule leaves the surface

Question 15

what are the two things that can affect the efficiency of a heterogeneous catalyst and why

Answer 15

1. poisoning: some of the catalysts can be filled with impurities that make them useless to use
2. promoters: some surfaces of the catalysts aren’t effective for the reaction to take place so promoters are used in order to produce active sites where the reaction can take place

Question 16

what do three-way catalytic converts do

Answer 16

they change unburned hydrocarbons into water and carbon dioxide, its also converts carbon, and carbon monoxide into carbon dioxide, and convert oxides of nitrogen into oxygen and nitrogen

Question 17

aluminum oxide catalyst absorbs more

Answer 17

water

Question 18

copper and nickel catalyst absorbs more

Answer 18

hydrogen

Question 19

what is an autocatalyst

Answer 19

when the reactions product act as a catalyst for the reaction

Question 20

what is an example of an autocatalyst reaction

Answer 20

the oxidation of ethanedioic acid by potassium manganate (VII) as manganese(II) formed is the catalysts

Question 21

what does the curve of concentration of reactant x time look for an autocatalyst reaction

Answer 21

page 21

Question 22

what are other explanations for the shape of the graph of an autocatalyst reaction

Answer 22

1. the reaction is between a solid and a liquid where the liquid needs to penetrate a specific place before the reaction happens
2. the reaction is extremely exothermic and the heat isn’t being controlled os the heat speeds up the reaction