STAGE 2 CHEMISTRY

ASSESSMENT TYPE 1: Investigations Folio

Issues Investigation - Student 2 Response

Magnesium Production in Spencer Gulf

Part A Article Analysis

Student Name: Source Number: 1

Student response
research skills
information source
(correctly formatted reference) / Perth Sunday Times, Aussie alloy under test 16/02/2003
relevant information highlighted in materials submitted
communication
description of information / Article is about a new Magnesium alloy being developed and why it is better than current Aluminium alloys
The uses of this alloy are mainly in the car industry
analysis
relevance
(the degree to which the source addresses the topic) / Compares using new Magnesium allow with traditional Aluminium alloys
Outlines advantages of Magnesium alloy (lighter and stronger)
possibility of bias
(evidence of a prejudiced or partial viewpoint that influences interpretation of the material) / Very in favour of new Magnesium alloy which indicates a bias
credibility
(the trustworthiness, i.e. credentials, education, experience, peer review etc. of the source) / Written for a highly regarded Sunday newspaper
The writer is very experienced
Lots of people have this opinion
other factors
(ease of access, clarity of language and presentation, use of diagrams) / Short and easy to read
No diagrams or pictures were used

Article Analysis

Student Name: Source Number: 2

Student response
research skills
information source
(correctly formatted reference) / The Advertiser, ‘Beware Toxic Dangers of Smelting’ 11/03/2002
relevant information highlighted in materials submitted
communication
description of information / This is a letter to the editor and gives really good reasons why the Magnesium smelter should not be located in Pt Pirie
analysis
relevance
(the degree to which the source addresses the topic) / Very good for negatives of the investigation
Most of the articles were strongly favoured of the Magnesium smelter
possibility of bias
(evidence of a prejudiced or partial viewpoint that influences interpretation of the material) / The article is very bias
Article did not contain any positives about the smelter
Author belongs to a Conservation group who always oppose this sort of development
credibility
(the trustworthiness, i.e. credentials, education, experience, peer review etc. of the source) / The Advertiser is a well-known and well respected newspaper
One person’s opinion and so is not credible
other factors
(ease of access, clarity of language and presentation, use of diagrams) / Very easy to access
Very short and easy to read letter
The language was very clear
No diagrams were used

Magnesium Production in Spencer Gulf

I have chosen to investigate Magnesium and it’s possible production in Spencer Gulf. It is a very light metal and it is non-toxic, non-magnetic and is very strong. This is why it is very useful in manufacturing. But Magnesium has advantages and disadvantages and that is why the production of Magnesium in Spencer Gulf is an important issue.

As well as being very light, Magnesium is also very reactive and so, unlike Gold and Silver, Magnesium is always found as a compound in nature.. This compound is called magnesite and is very hard to produce.

There are two main ways of producing Magnesium for it’s ore. Firstly the silicothermic process. Thisproduces magnesium oxide in a molten slag at temperatures of 1200ºC-1600ºC under low pressure to produce a Magnesium vapour. The Magnesium vapour is then condensed. This can produce very pure Magnesium.

The molten magnesium has to be protected from the air because it will react with oxygen. This can be done using sulphur dioxide but it can be a health hazard as it’s bad for the respitory system.Also it can cause acid rain. More recently it has been done with sulphur hexafluoride.

The equation for this is

Si(s) + MgO(s) → SiO2(s) + Mg(g)

The second process is more common. Magnesium is produced by electrolysis. Molten magnesium chloride is electrolyzed at 700 ºC. This process produces Magnesium that is not as pure as the other process. The Australian Magnesium Process is a process that was developed in Australia. It involves dissolving pure magnesite ore in hydrochloric acid to produce magnesium chloride. The magnesium chloride is then purified. It is then dehydrated and put into an electrolytic cell. You have to use electrolysis because Magnesium is very reactive and so needs a lot of energy to produce it. Chlorine gas released is at the other electrode and is then recycled and combined with hydrogen, from natural gas to produce HCland this can be used again.The Magnesium is produced at the cathode by a reduction reaction and chlorineis produced at the anode.

The half equation for the electrolysis reactionsare

Mg2+ + 2e  Mg

2Cl-  Cl2 + 2e

Different people have different opinions about whether Pt. Pirie should have a smelter. The map shows the Spencer Gulf and Pt. Pirie.

The map provided here has been removed from the exemplar for copyright reasons.

The magnesium ore mine is close to Pt Pirie and so it’s easy to get the ore to Pt Pirie (eg, by train or truck). Also, a new green power station would be built near Pt Pirie to provide the energy. This would also mean that there will be more jobs in the mine and the power station, so leading to more employment in the town. However, there are also some problems as well. Toxic emissions from the electrolysis can get into the air, food and water and there are concerns that some of the chemicals in the water-cooling unit could get into the gulf and cause water pollution. Dioxins and furans and POP’s cause air pollution and these can cause cancer and suppress the immune system. If sulfur hexaflouride is used it is a greenhouse gas and so it absorbs the sun’s heat and keeps it in the atmosphere and so contributes to global warming if it leaks out. This would cause the sea levels to rise and, as Pt. Pirie is on the coast, this could cause problems for housing and businesses.

One way of solving this problem would be to monitor the air, soil and water around the plant to detect any contamination. This could provide more employment. Or you could have a buffer zone around the plant to prevent air pollution from effecting local residents. One of the things that has been concerning Pt Pirie is the lead from other industries getting in the soil and effecting children and this wouldn’t produce any lead so that it would be a better industry for the town.

Conclusion

In my opinion, magnesium is a very valuable metal because of the many different ways in which it can be used. Setting up a production plant in a place such as Pt Pirie would have advantages and disadvantages. Economically it would be very good for the area because it would enable many more people to gain employment and take advantage of the mining boom. It would also be good economically for Australia because the Magnesium could be exported to other countries..Also it could replace other industries that are causing concerns at the moment, like lead.On the other hand it also causes a lot of pollution.

References

Perth Sunday Times, Aussie alloy under test 16/02/2003

The Advertiser, ‘Beware Toxic Dangers of Smelting’ 11/03/2002

This website is provided by the Australian Government through Geoscience Australia so it is a credible site and isn’t bias. It is a fact sheet that tells me almost everything I need to know about magnesium production in Australia.

This site explains about magnesium production and refining.

This gives details and reactions for the process of magnesium production.

Word count: Evaluations - 191

Report - 767

Total: 958

Page 1 of 6Stage 2 Chemistry annotated response

Ref:A121059 (revised January 2013)

© SACE Board of South Australia 2013

Performance Standards for Stage 2 Chemistry

Investigation / Analysis and Evaluation / Application / Knowledge and Understanding
A / Designs logical, coherent, and detailed plans for chemistry investigations.
Critically and logically selects and consistently and appropriately acknowledges information about chemistry and issues in chemistry from a range of sources.
Manipulates apparatus and technological tools carefully and highly effectively to implement well-organised safe and ethical investigation procedures.
Obtains, records, and displays findings of investigations using appropriate conventions and formats accurately and highly effectively. / Critically and systematically analyses data and their connections with concepts to formulate logical and perceptive conclusions and make relevant predictions.
Critically and logically evaluates procedures and suggests a range of appropriate improvements. / Applies chemistry concepts and evidence from investigations to suggest solutions to complex problems in new and familiar contexts.
Uses appropriate chemical terms, conventions, formulae, and equations highly effectively.
Demonstrates initiative in applying constructive and focused individual and collaborative work skills. / Consistently demonstrates a deep and broad knowledge and understanding of a range of chemistry concepts.
Uses knowledge of chemistry perceptively and logically to understand and explain social or environmental issues.
Uses a variety of formats to communicate knowledge and understanding of chemistry coherently and highly effectively.
B / Designs well-considered and clear plans for chemistry investigations.
Logically selects and appropriately acknowledges information about chemistry and issues in chemistry from different sources.
Manipulates apparatus and technological tools carefully and mostly effectively to implement organised safe and ethical investigation procedures.
Obtains, records, and displays findings of investigations using appropriate conventions and formats mostly accurately and effectively. / Clearly and logically analyses data and their connections with concepts to formulate consistent conclusions and make mostly relevant predictions.
Logically evaluates procedures and suggests some appropriate improvements. / Applies chemistry concepts and evidence from investigations to suggest solutions to problems in new and familiar contexts.
Uses appropriate chemical terms, conventions, formulae, and equations effectively.
Applies mostly constructive and focused individual and collaborative work skills. / Demonstrates some depth and breadth of knowledge and understanding of a range of chemistry concepts.
Uses knowledge of chemistry logically to understand and explain social or environmental issues.
Uses a variety of formats to communicate knowledge and understanding of chemistry coherently and effectively.
C / Designs considered and generally clear plans for chemistry investigations.
Selects with some focus, and mostly appropriately acknowledges, information about chemistry and issues in chemistry from different sources.
Manipulates apparatus and technological tools generally carefully and effectively to implement safe and ethical investigation procedures.
Obtains, records, and displays findings of investigations using generally appropriate conventions and formats with some errors but generally accurately and effectively. / Analyses data and their connections with concepts to formulate generally appropriate conclusions and make simple predictions with some relevance.
Evaluates some procedures in chemistry and suggests some improvements that are generally appropriate. / Applies chemistry concepts and evidence from investigations to suggest some solutions to basic problems in new or familiar contexts.
Uses generally appropriate chemical terms, conventions, formulae, and equations with some general effectiveness.
Applies generally constructive individual and collaborative work skills. / Demonstrates knowledge and understanding of a general range of chemistry concepts.
Uses knowledge of chemistry with some logic to understand and explain one or more social or environmental issues.
Uses different formats to communicate knowledge and understanding of chemistry with some general effectiveness.
D / Prepares the outline of one or more chemistry investigations.
Selects and may partly acknowledge one or more sources of information about chemistry or an issue in chemistry.
Uses apparatus and technological tools with inconsistent care and effectiveness and attempts to implement safe and ethical investigation procedures.
Obtains, records, and displays findings of investigations using conventions and formats inconsistently, with occasional accuracy and effectiveness. / Describes basic connections between some data and concepts and attempts to formulate a conclusion and make a simple prediction that may be relevant.
For some procedures, identifies improvements that may be made. / Applies some evidence to describe some basic problems and identify one or more simple solutions, in familiar contexts.
Attempts to use some chemical terms, conventions, formulae, and equations that may be appropriate.
Attempts individual work inconsistently, and contributes superficially to aspects of collaborative work. / Demonstrates some basic knowledge and partial understanding of chemistry concepts.
Identifies and explains some chemistry information that is relevant to one or more social or environmental issues.
Communicates basic information to others using one or more formats.
E / Identifies a simple procedure for a chemistry investigation.
Identifies a source of information about chemistry or an issue in chemistry.
Attempts to use apparatus and technological tools with limited effectiveness or attention to safe or ethical investigation procedures.
Attempts to record and display some descriptive information about an investigation, with limited accuracy or effectiveness. / Attempts to connect data with concepts, formulate a conclusion and make a prediction.
Acknowledges the need for improvements in one or more procedures. / Identifies a basic problem and attempts to identify a solution in a familiar context.
Identifies some chemical terms or formulae.
Shows emerging skills in individual and collaborative work. / Demonstrates some limited recognition and awareness of chemistry concepts.
Shows an emerging understanding that some chemistry information is relevant to social or environmental issues.
Attempts to communicate information about chemistry.

Page 1 of 6Stage 2 Chemistry annotated response

Ref:A121059 (revised January 2013)

© SACE Board of South Australia 2013