Making a reaction go faster-Part 3

Question 1

a catalyst is a substance that

Answer 1

increases the rate of a chemical reaction but is chemically unchanged at the end of the reaction

Question 2

a heterogeneous catalyst is

Answer 2

one that is in a different phase to that of the reactants

Question 3

a catalyst works by

Answer 3

providing an alternative route for the reaction which has a lower activation energy than the original route

Question 4

a reaction profile diagram is

Answer 4

an extension of an enthalpy level diagram which also shows the activation energy for the reaction

Question 5

for an endothermic reaction, the reactants on a reaction profile diagram will be positioned……………..than the products

Answer 5

lower than the products

Question 6

for a catalysed reaction, the reaction profile diagram has

Answer 6

a lower activation energy curve

Question 7

the two major economic advantages of using catalysts are:

Answer 7

• they increased the rate of reaction meaning more product can be made in the given time period
• reactions can take place at lower temperatures resulting in a decrease in the energy costs to the manufacturer

Question 8

in the Haber process,……………………………..is used as a heterogeneous catalyst

Answer 8

iron

Question 9

in the contact process ,……………………………is used as a heterogeneous catalyst

Answer 9

vanadium (V) oxide

Question 10

a solid catalyst works by

Answer 10

providing a surface on which the gas molecules can absorb and then react, then desorb as product molecules