Topics

What the report has to argue

What the report is

A written report, usually produced over two to three weeks, built from resource material your teacher supplies.
This is not a research task. Finding sources is not the work — processing and interpreting the information you are given is. You may bring in your own material, but the material provided is already enough.
It has no fixed content. What is fixed is the structure of the argument it has to make.

The three verbs

Verb	What it produces
Account	An accurate description of the chemical processes, with formulae and balanced equations. Correct, and it stops there.
Explain links	The chemistry connected to its consequences for people or the environment
Evaluate	A judgement — the size of the impact, the issues arising, what is uncertain, and a comparison between processes or responses

There are three ways to reach that last verb: elaborating on, comparing and contrasting, or analysing the links. Any one of them is enough, and choosing which suits your topic is worth thinking about before you write.

Equations are compulsory throughout

Even the bare account has to be supported by chemistry vocabulary, symbols, conventions and equations.
Once you are explaining links, those elements have to be integrated into the explanation rather than appended to it.
In a full evaluation the integration is consistent from end to end.
"Integrated" means the equation is doing explanatory work in the sentence around it, not sitting in a box on its own. Compare:
- Appended: "Carbon dioxide dissolves in seawater. The equation is CO₂ + H₂O ⇌ H₂CO₃."
- Integrated: "Because dissolved CO₂ reacts with water to form carbonic acid, $\text{CO}_2(g) + \text{H}_2\text{O}(l) \rightleftharpoons \text{H}_2\text{CO}_3(aq)$ , which then ionises to release H⁺, an increase in atmospheric CO₂ necessarily lowers the pH of the surface ocean."

The chain your report has to build

Every strong report has the same shape:

The chemical process — what reacts with what, with equations.
The consequence — what that process causes to happen in the world.
The impact — who or what is affected, and how much.
The response — what has been or could be done, and its own chemistry.
The evaluation — how big, how certain, and how the options compare.
The links live between the first two. The judgement lives in the last one.

Choosing a context

A good context has:

Chemistry you can actually explain at Level 3 — equilibrium, acids and bases, redox, thermochemistry, organic.
Equations you can write and balance.
Documented consequences, preferably with numbers.
A genuine trade-off or unresolved issue, which is what an evaluation needs.
Ideally a New Zealand dimension, which makes the impact concrete.

Context	Chemistry it runs on	The issue to evaluate
Ocean acidification	carbonate equilibria, Le Châtelier, weak acids	shellfish and aquaculture vs global CO₂ control
Nitrogen in freshwater	redox, the nitrogen cycle, the Haber process	food production vs water quality
Ozone depletion	catalytic cycles, bond energies, UV absorption	the Montreal Protocol's success vs its replacements
Acid rain	SO₂/NO_x oxidation, acid–base	emissions control cost vs ecosystem damage
Geothermal energy	dissolution, precipitation, H₂S chemistry	renewable energy vs arsenic and silica discharge
Green hydrogen / ammonia	electrolysis, Haber–Bosch, thermochemistry	decarbonising fertiliser vs energy cost

What the report has to argue

Covers AS91389

What the report is

A written report, usually produced over two to three weeks, built from resource material your teacher supplies.
This is not a research task. Finding sources is not the work — processing and interpreting the information you are given is. You may bring in your own material, but the material provided is already enough.
It has no fixed content. What is fixed is the structure of the argument it has to make.

The three verbs

Verb	What it produces
Account	An accurate description of the chemical processes, with formulae and balanced equations. Correct, and it stops there.
Explain links	The chemistry connected to its consequences for people or the environment
Evaluate	A judgement — the size of the impact, the issues arising, what is uncertain, and a comparison between processes or responses

There are three ways to reach that last verb: elaborating on, comparing and contrasting, or analysing the links. Any one of them is enough, and choosing which suits your topic is worth thinking about before you write.

Equations are compulsory throughout

Even the bare account has to be supported by chemistry vocabulary, symbols, conventions and equations.
Once you are explaining links, those elements have to be integrated into the explanation rather than appended to it.
In a full evaluation the integration is consistent from end to end.
"Integrated" means the equation is doing explanatory work in the sentence around it, not sitting in a box on its own. Compare:
- Appended: "Carbon dioxide dissolves in seawater. The equation is CO₂ + H₂O ⇌ H₂CO₃."
- Integrated: "Because dissolved CO₂ reacts with water to form carbonic acid, $\text{CO}_2(g) + \text{H}_2\text{O}(l) \rightleftharpoons \text{H}_2\text{CO}_3(aq)$ , which then ionises to release H⁺, an increase in atmospheric CO₂ necessarily lowers the pH of the surface ocean."

The chain your report has to build

Every strong report has the same shape:

The chemical process — what reacts with what, with equations.
The consequence — what that process causes to happen in the world.
The impact — who or what is affected, and how much.
The response — what has been or could be done, and its own chemistry.
The evaluation — how big, how certain, and how the options compare.
The links live between the first two. The judgement lives in the last one.

Choosing a context

A good context has:

Chemistry you can actually explain at Level 3 — equilibrium, acids and bases, redox, thermochemistry, organic.
Equations you can write and balance.
Documented consequences, preferably with numbers.
A genuine trade-off or unresolved issue, which is what an evaluation needs.
Ideally a New Zealand dimension, which makes the impact concrete.

Context	Chemistry it runs on	The issue to evaluate
Ocean acidification	carbonate equilibria, Le Châtelier, weak acids	shellfish and aquaculture vs global CO₂ control
Nitrogen in freshwater	redox, the nitrogen cycle, the Haber process	food production vs water quality
Ozone depletion	catalytic cycles, bond energies, UV absorption	the Montreal Protocol's success vs its replacements
Acid rain	SO₂/NO_x oxidation, acid–base	emissions control cost vs ecosystem damage
Geothermal energy	dissolution, precipitation, H₂S chemistry	renewable energy vs arsenic and silica discharge
Green hydrogen / ammonia	electrolysis, Haber–Bosch, thermochemistry	decarbonising fertiliser vs energy cost