Answer:
Step-by-step explanation:
Are you looking for sources of error? You'd need to evaluate the procedure itself. More info on this would be helpful!
Some common sources of error are ...
- Lack of temperature control (fixed by monitoring with thermometer, using a hot plate)
- Human traffic in room disrupting fine powders, etc. (decrease number of participants in room)
- Evaporation of substances over extended periods of time affecting yield