Planning an investigation

Planning an investigation

1. Planning and choosing equipment

   • when you are choosing equipment, you need to consider:
     • What is it for?
     • How many do you need?
     • How precise does it have to be?
     • What size does it have to be?
   • When you are planning to use equipment you should consider using the smallest piece of equipment as possible as this would be more accurate. This is the same as small built in error equipment- instead of using a cylinder, use a pipette

2. Choosing appropiate techniques

   • What are you investigating?
   • What methods are you using?
   • Do you have the equipment available for this technique?
   • Do you have enough time to carry out this technique?
   • Do you have the skills and technique to carry out this experiment?

3. Qualitative data

   • This can refer to things such as the value of something, colour observed or whether bubbles were produced or not
   • Another example of this would be a flame test. You have to make inference from observations as well as from measured results. This includes colours, smells, solids produced/dissolving, gasses produced- a flame test can tell us the cations present in a compound

4. Standard operating procedure (SOP)

   • Titrations
   • Handling of chemicals
   • Disposal of waste
   • Qualitative analytical tests
   • Preparing solutions

5. Hazard- the equipmrnt or substance that can cause harm, an example of this owuld be a hot plate

   • Risk- the harm that the hazard could cause and the chance of it happening- the risk of the hot plate is getting burnt

6. Variables in an investigation (measuring a tennis ball with a ruler)

   • The independent variables are what you can change
   • Height the ball is dropped at
   • Type of ball
   • Size of ball
   • Surface the ball dropped on
   • The dependent variable is something you measure
     • How high the ball will bounce
   • You can only change one variable to test a hypothesis' validity
   • Control variables
     • These controls are the independent variables. But with controls. An example would be dropping the ball from the exact same height