As part of your assessment for VCE Chemistry Units 3/4, you are required to design your own experimental investigation. This is a great opportunity to apply the theory you have learnt throughout the year into practise.

There’s quite a process you need to undergo to plan, execute and summarise your experiment, so this article will take you through everything you need to know.

Investigation Requirements

Although this assessment is very open ended, VCAA has left some guidelines that you must follow. Don’t worry though, you still have a lot of autonomy – following the study design will just help you maximise your marks.

Your inquiry must be 'related to the production of energy and/or chemicals and/or the analysis or synthesis of organic compounds, and should be inspired by a contemporary chemical challenge or issue.' This is quite a broad requirement, so you can pretty much choose any experiment. As you can see, it does however need to relate to things you've learnt in class and be related to chemical processes used in society. 

Structure

You need to present your investigation in the form of a scientific poster (can be produced electronically or as a hard copy). Scientific posters are used prominently in the real world for scholars to present their research to an audience. It is not as detailed as a traditional report and usually contains lots of visual elements.

Your scientific poster must be limited to 600 words. This is not a lot of words, so you must be very concise in your language.

For example, rather than saying:

If the concentration of hydrochloric acid in the beaker increases, then carbon dioxide will be produced at a faster rate. As the concentration of hydrochloric acid increases, there are more reactant particles available to react, which increases the frequency of successful collisions. (42 words)

You can rephrase it as:

If the concentration of hydrochloric acid is increased, then carbon dioxide will be produced at a faster rate. This is due to the increase in acid particles available to react. (30 words)

Tables, graphs, and image captions do not count for your total word count, so it would be wise to implement these into appropriate sections.  For instance, having your results presented in a table rather than a paragraph summary would be a smarter choice.

Your final poster must include: An introduction, methodology, results, communication statement, discussion, conclusion, and references. VCAA requires that you use the following structure for your poster:

The centre of the poster must occupy about a quarter of the total poster space. Here, you will need to summarise your findings in one sentence. 

Investigation Ideas

The very first thing you need to do is decide on what you want to investigate. Make sure you choose an area of chemistry and topic that you are passionate about (you don’t want to get tired of it!). Also, make sure it fits VCAA's requirements. 

Here are some general ideas that you can consider:

• How the production of a chemical product can be optimised using the concepts covered in collision theory (a good one to relate sustainability too, as the more efficient a process is, the better for the environment).
• How the structure of a molecule impacts its heat of combustion/boiling point.
• Which types of organic compounds release the most CO2 emissions upon combustion.
• Using a titration to calculate the amount of an organic compound in a product (i.e., ascorbic acid in Vitamin C, or acetic acid in vinegar)
•  Compare the fermentation rates of glucose, sucrose, and fructose. How can the product of glucose fermentation be used as a fuel source? 
• How does the chemicals used in electrolysis impact the amount of electricity consumed?

Designing Your Investigation

After you’ve decided on what you want to investigate, you need to come up with the title. The title must be a research question, that shows the connection between your dependent (what you are measuring) and independent (what you are changing) variables.

A simple example is:

How does the structure of an organic compound affect its boiling point?

Just by reading this title, you can deduce that the independent variable is structure, while the dependent variable is the boiling point.

Next, you should focus on coming up with your methodology, i.e. how you are going to conduct your experiment, collect results and analyse them. You will need to do some research (as cool as it may be, you don’t want to accidently blow anything up).

Here are some things to think about:

•  What apparatuses/chemicals will you need?
•  What is your experimental set up?
•  What variables are you going to control to eliminate errors?
•  How are you going to record your results, and how often? For example, if you need to measure the temperature of something, will you do it over time increments, or record the time it takes for the temperature to reach a certain value?
•  What safety considerations do you need to make?

After you have your methodology sorted, you are ready to begin your investigation! While you do you experiment, don’t forget to record your results, make note of any experimental errors, and do multiple trials (if possible).

Marking Criteria

Your poster will be marked based on:

• How clear and relevant your research question is.
• Your understanding of your experiment, including its methodology, context, purpose, and significance.
• How well you’ve collected and analysed both quantitative and qualitative data relevant to your research question.
• The presentation of your investigation results and identification of errors and limitations.
• How well you have analysed and linked your investigation to relevant scientific concepts (including energy/food).

Since your teacher will be marking this poster, it is important to consult with them to know what they are looking for.

Tips

•    Make sure that your poster is legible (i.e. use a clear font, correct formatting etc)
•    Don’t make your experiment too complicated, as it will be harder to execute.
•    Make sure that you consult with your teacher before beginning your experiment. Let them know your idea so they can help you.
•    Make sure that have access to the equipment and chemicals you require.
•    Have a good understanding of the theory that explains your experiment.  

The scientific investigation that you will undertake is a great way to put what you’ve learnt into practice. It’s definitely one of the most exciting assessments you’ll do this year. Just don’t forget to have fun with it and choose a topic that you are passionate about.  

If you'd like some more detailed advice on how to write each section, you can download some notes here.

FAQs

What should my research question focus on?

Your research question should relate to the production of energy, chemicals, or the analysis/synthesis of organic compounds. You should try to consider contemporary chemical challenges, such as sustainability or alternative energy sources.

How can I choose a topic that I'm passionate about?

Think about topics covered in class that intrigued you. Consider issues in your community or global challenges related to chemistry. Make a list of ideas and see which ones excite you the most!

How do I need to structure my scientific poster?

Organize your poster into clear sections: Introduction, Methodology, Results, Communication Statement, Discussion, Conclusion, and References. Use headings and bullet points to enhance readability.

How can I ensure my methodology is clear and comprehensive?

Detail every step of your experiment, including the apparatus and chemicals used, control variables, and how you will record data. Clarity is key for reproducibility.

What types of data should I collect during my experiment?

Collect both quantitative data (numerical measurements) and qualitative data (observations). Ensure they are relevant to your research question and help answer it effectively. You should also make note of any experimental errors.

How do I present my results visually?

Use tables for data and graphs for trends. Bar charts, line graphs, and pie charts are effective ways to display your results. Make sure they are clearly labeled and easy to interpret.

How will my poster be assessed?

Your poster will be evaluated based on clarity of the research question, understanding of the experiment, data collection and analysis, presentation of results, and linking to relevant scientific concepts.