Home > Subjects > Chemistry > Level 3 > 3.1 Practical investigation > Key tips
- Subject: Chemistry
- AS: AS90694
- Level: 3
- Credits: 4
- Internal
Chemistry 3.1 Carry out an extended practical investigation involving quantitative analysis
Key tips
- Revise level 2 work on analytical chemistry.
- Before you start the investigation, make sure you clearly understand what is expected of you and what evidence you must record during the investigation.
- Follow the written instructions that will be given to you by your teacher.
- Keep to the marking schedule and the time frame given to you by your teacher.
- A learner cannot be awarded the standard without a log book. The log book is to be filled out as you go and should not be computer generated. It contains raw data, details of your investigation, and problems/ solutions arising throughout the investigation.
- A possible trend must be considered with the purpose of the investigation, although the conclusion may be that there is no trend.
- If your analytical technique involves titration – a titre value of less than 5 mL is not acceptable as this would barely exceed the uncertainty of measurement involved ifs this was calculated. In back titrations, the difference between titre values also needs to exceed 5 mL.
- If your titres are more than 30 mL, you should do some more trials and aim to have titre values less than this. You may need to change the concentration of your known solution.
- Make sure you plan ahead and make up enough of your stock solutions so that you do not run out and have to restandardise.
- It is expected that you will make your own solutions up for standardisation and that you will carry out a standardisation procedure as part of this standard.
