Question 1

Adding which one of the following substances to copper(II) sulfate solution will not result in the formation of a precipitate?

Accepted Answer

$NH_4Cl(aq)$

Answer

Zn(s)

Answer

$BaCl_2(aq)$

Answer

$Na_2CO_3(aq)$

Question 2

Excess silver nitrate $(AgNO_3)$ is added to a 250.0 mL sample of river water. The precipitate of silver chloride (AgCl) was dried and weighed. Its mass was found to be 20.37 g. What is the concentration of chloride ions in the river water?

Accepted Answer

20.2 g/L

Answer

81.5 g/L

Answer

0.142 g/L

Answer

0.569 g/L

Question 3

The absorption spectrum of a coloured compound is shown below.
What is the best description of the colour of this compound?

Accepted Answer

green

Answer

violet

Answer

orange-red

Answer

blue

Question 4

If the concentration of this compound is to be determined by UV-visible spectroscopy, which one of the following wavelengths would be most suitable to use?

Accepted Answer

460 mm

Answer

550 mm

Answer

670 mm

Answer

420 mm

Question 5

Dissolved calcium ions are responsible for the ‘hardness’ of water. The concentration of calcium ions in a dam was determined by atomic absorption spectroscopy (AAS). Several solutions of known concentration of calcium ions were tested, and the results were plotted as a calibration curve, as shown below.
25.0 mL of the dam water was diluted to 100 mL with distilled water. The absorption of the diluted solution, measured under the same conditions as the standards, was 0.3.
What was the approximate concentration of calcium in the dam water?

Accepted Answer

64 ppm

Answer

16 ppm

Answer

30 ppm

Answer

4 ppm

Question 6

Which of the following industrial processes is not likely to add to mineral levels in New South Wales waterways?

Accepted Answer

extracting tea-tree oil in northern New South Wales

Answer

operating desalination plants

Answer

manufacturing fertilizer near Newcastle

Answer

concentrating copper ore at Broken Hill

Question 7

Which of the following solids would be the easiest to distinguish in the flame test?

Accepted Answer

copper chloride

Answer

strontium carbonate

Answer

strontium chloride

Answer

lithium chloride

Question 8

Which of the following combinations of solutions will form a coloured precipitate when mixed?

Accepted Answer

copper(II) sulfate and sodium hydroxide

Answer

copper(II) nitrate and zinc nitrate

Answer

silver nitrate and sodium chloride

Answer

calcium nitrate and sodium carbonate

Question 9

The identity of an ion can be determined by testing whether it forms precipitates and, if it does, by taking note of the colour of the precipitate. Which of the following tests could be used to determine the identity of a cation?

Accepted Answer

Add hydrochloric acid, then ammonia

Answer

Add silver nitrate, then either barium chloride or nitric acid

Answer

Add hydrochloric acid, then sodium hydroxide

Answer

Add silver nitrate, then nitric acid

Question 10

Which of the following ions cannot be identified using complexation reactions?

Accepted Answer

$K^+$

Answer

$Ag^+$

Answer

$Fe^{3+}$

Answer

$Cu^{2+}$

Question 11

Select the correct statement about a conductometric titration

Accepted Answer

It is not necessary to approach the equivalence point by adding one drop of solution at a time.

Answer

An indicator is added to highlight the point at which the electrical conductivity is at a minimum.

Answer

The anions in the titration will have no impact upon the conductivity.

Answer

The conductivity of the solution under the burette increases with each addition but not by the same amount.

Question 12

Which of the following options describes how to prepare a calibration curve to be used with an atomic absorption spectrometer?

Accepted Answer

Test a series of solutions of known, but varying concentrations.

Answer

Run a series of unknown concentration solutions through the instrument.

Answer

Draw a straight line from the origin to the absorbance of the unknown solution

Answer

Compare the results obtained from more than one spectrometer.

Question 13

Which of the following will not react with acidified potassium dichromate $(K_2Cr_2O_7)?$

Accepted Answer

$(CH_3)_3COH$

Answer

$(CH_3)_2CHOH$

Answer

$CH_3CH_2CH_2OH$

Answer

$(CH_3)_3CCH_2OH$

Question 14

Which of the following will not immediately turn red bromine water colourless?

Accepted Answer

$C_6H_{14}$

Answer

oct-1-ene

Answer

$C_5H_{10}$

Answer

$CH_2CHCH_3$

Question 15

Which of the following instruments would be the best suited to measure the concentration of copper ions in a solution?

Accepted Answer

UV-visible spectrophotometer

Answer

proton NMR

Answer

mass spectrometer

Answer

infrared spectrometer

Question 16

Under analysis by proton NMR spectroscopy, which of the following molecules contains the greatest number of hydrogen environments?

Accepted Answer

$CH_3CH_2OH$

Answer

$CH_3CH_2COCH_2CH_3$

Answer

$CH_3CH_2CH_2CH_3$

Answer

$CH_3CHClCH_3$

Question 17

Hydrogen gas can be produced from the endothermic reaction between ammonia gas and steam. The equation is:
$2NH_3(g)$ + $4H_2O(g)$ ⇌ $2NO_2(g)$ + $7H_2(g)$
What conditions are most likely required to provide a high yield of hydrogen?

Accepted Answer

high temperature, low pressure and an excess of steam

Answer

low temperature, low pressure and an excess of $NO_2$

Answer

high temperature, high pressure and an excess of ammonia

Answer

low temperature, high pressure and excess of steam

Question 18

Which of the following reactions has an atom economy of 100%?

Accepted Answer

addition reaction of ethene and chlorine gas

Answer

substitution of chlorine on methane using chlorine gas

Answer

condensation reaction between ethanol and ethanoic acid

Answer

reaction of chloroethane and ammonia

Question 19

Which statement about propan-1-ol and propan-2-ol is not true?

Accepted Answer

The fingerprint region of the IR spectra will be identical for both compounds.

Answer

The mass spectra of both will show a peak at a mass-to-charge ratio of 60

Answer

The carbon-13 NMR spectrum of propan-1-ol has three peaks, and that of propan-2-ol has two peaks.

Answer

The proton NMR spectrum of propan-1-ol has four peaks, and that of propan-2-ol has three peaks.

Question 20

In the mass spectrum of an organic compound, the signal produced by the unfragmented molecular ion and the signal produced by the most abundant particle correspond respectively to the:

Accepted Answer

parent (molecular) ion peak and base peak

Answer

main ion peak and base peak

Answer

base peak and parent (molecular) ion peak

Answer

parent (molecular) ion peak and main ion peak

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