Problem: Topic 3: Dot point 3-4 (1 Viewer)

[Exeter]

- analyse information to evaluate the reliability of the results of the above (sulfate content in lawn ferilisers) investigation and to propose solutions to problems encoutered in the procedure


cant find any books that have this

 

[Huy]

i'll write up my notes for this experiment, they're crumby but the teacher accepted it.

'sulfate is detected by adding a drop of barium nitrate or chloride solution'

problems:
* titration work, the end point was difficult to determine.
* wide variation within some results (end points between different groups in the class who had performed the same experiement)
* most results were between 5-10% of each other
* repeatability was reasonably good
* time between taking of aliquot and titration effected the result
e.g. aliquot taken and experiment performed, or aliquot taken and experiment performed the next day.
* cloudy solution after alcohol

this isn't the best dot point, but that's what my teacher had up on the board, so that's all we had to write for it

sorry about the depth of content, but that's all we had on this one. it's not much, but i guess you can elaborate on each point further.

 

[kini mini]

It depends, as Huy sort of implied, on the exact procedure you use. Go through the procedure and ask yourself what could go wrong at each stage.

http://hsc.csu.edu.au/chemistry/core/monitoring/chem943/943net.html#net5

gives a procedure, Pathways pp. 246-7 gives procedure and structured Q & A on problems with the procedure.