weak points from past papers

Question 1

what reduces effectiveness of catalyst

Answer 1

poison

Question 2

what is methane

Answer 2

natural gas

Question 3

what is nucleon

Answer 3

protons + neutrons

Question 4

property of platinum

Answer 4

good catalyst

Question 5

what to mention in terms of collision theory

Answer 5

• frequency of collisons
• activation energy
• less/more ek

Question 6

what is a saturated solution

Answer 6

solution containing maximum amount of solute dissolved at a given temp

Question 7

why crystals form when the saturated solution cools down

Answer 7

solubility decreases as temperature decreases

Question 8

what does coke do in blast furnace

Answer 8

• releases heat
• reduces iron (III) oxide
• reacts with CO2 to form carbon monoxide

Question 9

coke burning

Answer 9

C + O2 -> CO2

Question 10

reduction of carbon dioxide to carbon monoxide

Answer 10

CO2 + C -> 2CO

Question 11

reduction of iron (III) by carbon monoxide

Answer 11

Fe2O3 ++ 3CO -> 2Fe + 3CO2

Question 12

thermal decomposition of calcium carbonate to produce calcium oxide

Answer 12

CaCO3 -> CaO + CO2

Question 13

formation of slag

Answer 13

CaO + SiO2 -> CaSiO3

Question 14

overall equation of extraction of aluminium from aluminium oxide

Answer 14

2Al2O3 -> 4Al + 3O2

Question 15

oxygen produced at anode during aluminium extraction equation

Answer 15

2O-2 -> O2 + 4e-

Question 16

what is nitric acid

Answer 16

HNO3

Question 17

what is the random of motion of particles called

Answer 17

brownian motion