Component: Chemistry Skills

Question 22

Written Paper Section I Question 22 - 2010 HSC

(a) Name a common use for the class of compounds to which methyl propanoate belongs. (b) Explain why reflux is necessary in the production of methyl propanoate. (c) Name and draw the structural formulae of the two reactants used to prepare methyl propanoate.

Question 23

Written Paper Section I Question 23 - 2010 HSC

(a) Write a balanced equation for the complete combustion of 1-butanol. (b) Given heats of combustion of three fuels in kJg-1 and that of 1-butanol in kJmol-1, justify which fuel is likely to be 1-butanol.

Question 28

Written Paper Section I Question 28 - 2010 HSC

Describe identified steps in a titration flowchart to determine the concentration of an unknown hydrochloric acid solution. Determine the concentration of hydrochloric acid used, given volume and concentration of a sodium carbonate standard solution.

Question 29

Written Paper Section I Question 29 - 2010 HSC

(a) Assumptions made in a flowchart of the process to determine the amount of sulfate in a sample of lawn fertiliser. Explain how the assumptions affect the validity of the process. (b) Using the percentage composition of sulphate in the sample, determine the mass of the dried precipitate produced.

Question 30

Written Paper Section I Question 30 - 2010 HSC

(a) Compare the process of polymerisation of ethylene and glucose. (b) Explain the relationship between the structures and properties of three polymers from ethylene and glucose, and their uses.

Question 31

Written Paper Section I Question 31 - 2010 HSC

(a) Calculate the percentage of total dissolved solids in a filtered sample of dam water. Describe a chemical test to determine the presence of chloride ions in the sample. (b) Name an ion other than chloride that commonly pollutes waterways. Identify its source and the effect of its presence on water quality.