Questions Corrections 2020

Question 1

Flame colour produced by copper sulphate solution

Answer 1

Green

Question 2

Results for copper sulphate solution and calcium iodide solution when sodium hydroxide is added

Answer 2

Copper sulfate solution = blue precipitate

Calcium iodide solution = white precipitate

Question 3

Solution that would show the presence of sulfate ions when added to dilute HCL and copper sulfate mixture

Answer 3

Barium Chloride

Question 4

Hexane and bromine water reaction observations

Answer 4

Hero one water remains colourless

Question 5

Compare ethane with ethene in terms of their reactions

Answer 5

Both react with oxygen in complete combustion reactions to produce water and CO2
Both react in incomplete combustion which is more likely ethene
Ethene can react with hydrogen, water, halogens and can polymerise

Question 6

Explain how reducing the amount of sulphur in fossil fuels reduces the erosion of limestone

Answer 6

Sulfur reaction with oxygen to for, sulfur dioxide
So less sulfur dioxide emitted
So less acid rain
So less limestone reacts with acid rain

Question 7

Explain why oxides of nitrogen are formed in car engines

Answer 7

High temperatures
So nitrogen reacts with oxygen

Question 8

Ethanoic acid and zinc carbonate produce what gas

Answer 8

Carbon dioxide

Question 9

Why is The rate of reaction with 0.01mol/dm is greater than the rate of reaction with 0.01mol/dm ethanoic acid

Answer 9

Methanol acid has a lower pH
Mathsnoic acid has a higher concentration of hydrogen ions
Therefore more collisions per unit time