Why chemicals should never be placed directly on the balance pans?

Question

this is a chemistry laboratory subject

Answer 1

Because chemicals react with eachother, it is bad practice to place chemicals directly on the balance pans. Residual chemicals from a previous experiment could be resident on the pan, resulting in contamination of your chemical, or worse, an unwanted chemical reaction. This is why the majority of experiments require glass containers for chemicals. Most chemicals to not adhere to glass like they might do to metal, and glass can be more easily identified as clean.

Answer 2

a few reasons....
1. the chemical and the balance pan will react esp if metal!
2. prevent contamination..
3.lets you get it all off the scale so you know exactly how much you've got..imagine leaving 1gram of KOH on the pan ...not gonna have the right results...
4. if theres wind or anything like that, it might get blown off whereas if in a crucible it wont..
5..do you wana clean up a piece of equipment which can cost rediculous amounts of money depending on the sensitivity?