Assessment Tips

11SCI - Chemical Tūhura

Finn LeSueur


There are five topics in Pūtaiao 102

  1. Genetics (ext.) – finished in Term 1
  2. Microbes (int.) – finished yesterday
  3. Chemistry Tūhura (int.) – we were half-way through this topic when the lockdown began in Term 1
  4. Mechanics (ext.)
  5. Chemical Reactions (int.)

AS 90930

Chemistry Tūhura

(The 2nd half)

Internal, 4 Credits

For the assessment, you must:

  1. Conduct a Chemistry whakamātau (2 periods)
  2. Write a report on the whakamātau and the data you have gathered (1 period)

To get an Achieved, you must:

  1. Write the method of your whakamātau
  2. Identify variables (Independent, Dependent and Control)
  3. Make repeat measurements and calculate the average
  4. Describe the trend in the results/data
  5. Write the conclusion based on the data collected

To get an Merit, you must:

  1. Write the method of your whakamātau to a higher quality
  2. Identify variables and describe how the control variables have been controlled
  3. Make accurate, repeat measurements and calculate the average
  4. Describe the trend in the results/data
  5. Write the conclusion based on the data collected

To get an Merit, you must:

  1. Explain how the control variables that could have significantly affected the results have been controlled
  2. Explain the techniques/methods that were used to ensure the accuracy of the results obtained

To get an Excellence, you must:

  1. Complete everything up to Merit level, plus:
  2. Explain your results using the “Collision Theory”
  3. Discuss the techniques/methods you have used to ensure the results you obtained are reliable and valid
  4. Discuss on how your method could improve

Step 1: Aim & Hypothesis

In your group:

  1. Title your whakamātau
  2. Come up with an aim (What are you investigating? Be specific.)
    • Get this from your instruction card
  3. Come up with a hypothesis (What do you predict? Be specific.)
    • I think that the rate of reaction will [increase/decrease] when the [surface area/temperature/concentration] [increases/decreases].

Step 2: Variables

  • Independent Variable: The variable that you will change. What are we changing? Include units, measurement apparatus & range of measurements.
  • Dependent Variable: The variable being measured. What are you measuring? Include units & measurement apparatus.

Step 3: Control Variables & Reliability

  • Control Variable: Things that you are keeping constant. What will you not change throughout your whakamātau?
  • Reliability: An whakamātau is reliable if the results are within x seconds of each other when the method is repeated. The same method must give the same results each time.

Step 4: Method

  • Give you method as a numbered list,
  • List what equipment you will need (e.g. a 100ml beaker; 25ml of diluted \(HCl\)),
  • Break things up into small steps and say when you repeat a set of steps,

Step 4: Continued

  • State your range of measurement for your independent variable, its units and how you will measure it,
  • States some control variables and how to control them during the whakamātau.

Step 5: Data/Results

  • Design a table to record your results before you start the whakamātau,
  • You will need to think about how many trials you are going to do, how many measurements you will make and calculating an average.
Trial 1 Trial 2 Trial 3 Average
Small Chips
Large Chips

Average: Add up all your trial times (in seconds) and divide by the number of trials.

Step 6: Data/Conclusion

  • Needs to link to your aim and reflect the data you gathered.
  • In our whakamātau we investigated [your-aim-here] and we found that when the [temperature/surface area/concentration] was [increased/decreased] that the reaction went [slower/faster]. This tells us that the rate of reaction [increased/decreased]. This is reflected in our results, for example [two-pieces-of-data-compared-here].

If you have successfully filled out the document as we have discussed, you now have a merit!

This next step is for excellence!

Step 7: Discussion/Evaluation

  • Describe collision theory and how the particles changed between each test of your independent variable. E.g. When the temperature is high… and when the temperature is low..
  • Is your data reliable? Talk about the how similar all the data is for each test of your independent variable, were any mistakes made? It’s okay to be honest here.
  • Why is the method valid? Why would it produce the same results if tried again today? Talk about control variables and what they are doing to make the whakamātau valid.