Respuesta :

Answer:

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