Which of the following diatomic molecules would you expect to have the largest bond energy?

Which of the following molecules would you expect to have the shortest bond length for the oxygen-oxygen bond?

Which of the following molecules would you expect to have the largest oxygen-oxygen bond energy?

Which of the following diatomic molecules would you expect to have the largest bond length?

Conclusion

Your conclusion should answer all parts of your aim, and should state the (numerical) results. Think of it as a spoiler for the whole lab report!

For example:

If the aim is: Determine the concentration of Vitamin C in a fruit juice via a redox titration against N-bromosuccinimide.

The conclusion might be: Berri orange juice (2000 μL aliquots, in triplicate) was titrated against a 0.104 M solution of N-bromosuccinimide. The concentration of Vitamin C in the fruit juice was determined to be 55.0 mg/L.

Discussion

This is where you discuss and give meaning to the results. You should also detail any experimental errors and make any other relevant comments about the experiment. Include possible improvements. Ensure you are not re-stating the method.

Discussion points to consider: (Note: The points below are not intended as questions! They are here to give guidance on what to include in your discussion. Do not simply list answers - incorporate them into a full discussion.)

• Relate results back to the aim and introduction of the experiment – what was trying to be done, did the results support the aim of the experiment?
• Comment on the %w/v of acetic acid in the dressing. How confident are you with the results? Were reasonable values obtained? 
• What do the colour changes represent? How does this affect indicator choices in this experiment? Why did the indicators change between the two titrations?
• What factors may have affected the final results? What are some sources of error that may have been encountered, and how would they have impacted the results?

Discussion marking rubric:

Maximum of 300 words (+/- 10 %).

For guidance on writing a meaningful discussion, please refer to the following resources:

• SoC: Undergraduate Student Handbook
• RLO: Writing a Science Lab Report
• RLO: Writing for Assignments

Chemistry Drawing Question.

Equal volumes of solutions of sodium hydroxide (NaOH) and sodium chloride (NaCl) are mixed. The initial concentrations of the solutions are identical.

What is the final concentration of sodium ions?

Q2. A student calculated a weight percentage of acetic acid in the dressing of 2.3 %w/v. Considering that commercial salad dressings range from 4-8 %w/v, this value is slightly low and an error has likely occurred.

Assign the following sources of error into the three categories (i.e. in the table, enter in the category number, without the full stop):

1. An experimental/scientific source of error. Difficult to avoid without significant experimental changes.
2. Operator/human error. Likely to cause only minor deviations and can likely be corrected for with sufficient care and training.
3. An insignificant source of error.

Questions

Q1. Out of the following five titres, which three are considered concordant?

Note: Marks will be deducted for incorrect answers.

Skills Tests

Record the satisfactory completion of your skills tests here. Your TA will check this against their records.