How many NESA Chemistry questions cover Products of Reactions Involving Hydrocarbons?

AusGrader has 21 NESA Chemistry questions on Products of Reactions Involving Hydrocarbons, all with instant AI grading and detailed marking feedback.

NESA Chemistry Products of Reactions Involving Hydrocarbons

5 sample questions with marking guides and sample answers

2025

SCSA

1 mark

Which of the following will decolourise a solution of bromine water?

1.0 mol L $^{-1}$ $Fe(NO_3)_3$ solution

1.0 mol L $^{-1}$ KCl solution

$CH_3CH_2CH_2CH_2CHO$

$CH_3CH_2CHCHCH_3$

Q18

2021

QCAA

Paper 1

1 mark

Q18

1 mark

Identify the major product when 2-methylbut-2-ene reacts with water under acidic conditions.

(CH $_3$ ) $_2$ CHCOCH $_3$

(CH $_3$ ) $_2$ C(OH)CH $_2$ CH $_3$

(CH $_3$ ) $_2$ CHCH(OH)CH $_3$

(CH $_3$ ) $_2$ C(OH)CH(OH)CH $_3$

Q21

2025

NESA

2 marks

Q21

2 marks

Consider the following organic reaction.

$\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3 + \text{Br}_2 \xrightarrow{\text{Reaction condition X}} \text{CH}_3\text{CH}_2\text{CHBrCH}_3 + \text{HBr}$

In the space provided, identify reaction condition X and name the organic product.

Reaction condition X	IUPAC name of organic product

Reaction condition X	IUPAC name of organic product
UV light	2-bromobutane

Marking Criteria

Descriptor	Marks
Correctly identifies both the reaction condition AND product	2
Correctly identifies either the reaction condition OR product	1
None of the above	0

Q37

2025

NESA

4 marks

Q37

4 marks

Compound A has the molecular formula $\text{C}_5\text{H}_{10}$ . The information below shows some chemical reactions beginning with this compound.

Compound A reacts with $\text{H}^+/\text{H}_2\text{O}$ to produce compounds B and C.
Compound B does not react with $\text{H}^+/\text{Cr}_2\text{O}_7^{2-}$ .
Compound C reacts with $\text{H}^+/\text{Cr}_2\text{O}_7^{2-}$ to produce compound D.
Compound D does not react with $\text{Na}_2\text{CO}_3(aq)$ .

Determine the structure of compound A. Justify your answer using all the data given.

Compounds B and C are alkanols.

Compound B cannot be oxidised – so B must be a tertiary alkanol, therefore there must be branching.

Compound C can be oxidised but not to a carboxylic acid (no reaction with carbonate) – so the oxidation product is a ketone, so compound C is a secondary alkanol.

To explain the alkanols produced above, the C=C in compound A is not in the terminal position.

Therefore compound A is 2-methylbut-2-ene (C $_5$ H $_{10}$ ).

Marking Criteria

Descriptor	Marks
Correctly determines the structure of compound A AND Correctly justifies the structure using all the data provided	4
Correctly determines the structure of compound A AND justifies the structure using some of the data provided OR Correctly interprets all of the data provided	3
Correctly interprets some of the data provided	2
Provides some relevant information	1
None of the above	0

Q39

2023

SCSA

15 marks

Q39

Ethanol can be produced either from plant materials or from petrochemical sources.

Q39a

When ethanol is produced from plant sources, the material is ground up. The starches and cellulose in the material are then converted into sugars. Yeast or zymase is mixed with the sugars at 25 to 37 °C and a pH of between 3 and 5 at atmospheric pressure. The products of the fermentation process are ethanol and carbon dioxide.

Q39b

Ethanol can also be produced by the endothermic hydration of ethene. This is carried out at 250 to 300 °C and 6000 to 7000 kPa in the presence of an acid catalyst.

Q39a (i)

2 marks

Justify the conditions used for fermentation.

Zymase are enzymes, which are only effective in a narrow pH band and temperature band.

Marking Criteria

Descriptor	Marks
Recognises that yeast or zymase are enzymes	1
Recognises that enzymes are only effective in a narrow pH band and temperature band, or recognises that without the enzymes, the reaction either does not proceed or is too slow to be viable	1

Q39a (ii)

2 marks

Write an equation for the fermentation process, using $C_6H_{12}O_6$ as the sugar. Use condensed structures in your equation.

$\text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 2 \text{ CH}_3\text{CH}_2\text{OH} + 2 \text{ CO}_2$

Marking Criteria

Descriptor	Marks
Correct reactants and products	1
Correct balancing	1

Q39b (i)

3 marks

Write an equation for the hydration of ethene. Use condensed structures in your equation.

$\text{CH}_2\text{CH}_2 + \text{H}_2\text{O} \rightleftharpoons \text{CH}_3\text{CH}_2\text{OH}$

Marking Criteria

Descriptor	Marks
Correct reactants	1
Correct products	1
Uses condensed structures in equation	1

Q39b (ii)

5 marks

Justify the temperature and pressure used for the hydration of ethene.

high pressure increases rate of reaction as there are more particles per unit volume, therefore a greater frequency of collisions. It also increases yield due to it favouring the direction with the fewer number of gas particles which is the product side of the reaction. High temperature also means particles are moving more rapidly and collide more often, and more particles having sufficient energy for successful collisions, a greater proportion of collisions will be successful, increasing reaction rate.

Because hydration of ethene is endothermic, high temperature will favour the formation of the products.

High temperature favours both rate and yield, however, a moderate temperature will still produce an economical yield.

Marking Criteria

Descriptor	Marks
Recognition that high pressure increases rate of reaction as there are more particles per unit volume, therefore a greater frequency of collisions	1
Recognition that high pressure also increases yield due to it favouring the direction with the fewer number of gas particles which is the product side of the reaction	1
Recognition that high temperature will increase rate as the particles are moving more rapidly and collide more often, as well as more particles having sufficient energy for successful collision, so greater proportion of collisions will be successful	1
Recognition that because hydration of ethene is endothermic, high temperature will favour the formation of the products	1
Recognition that, although high temperature favours both rate and yield, a moderate temperature will produce economical/safe yield	1

Q39c

3 marks

State three reasons why the fermentation process to produce ethanol is more common than the hydration of ethene.

Fermentation requires less energy input than hydration of ethene, fermentation costs less than hydration of ethene, and fermentation is a 'greener' process than hydration of ethene. Furthermore, fermentation uses a renewable feedstock while hydration of ethene does not.

Marking Criteria

Descriptor	Marks
1 mark for each correct point (any 3 of): Fermentation requires less energy input than hydration of ethene Fermentation costs less than hydration of ethene Fermentation is a 'greener' process than hydration of ethene Fermentation uses a renewable feedstock while hydration of ethene does not	3

NESA Chemistry Products of Reactions Involving Hydrocarbons

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