ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: lauzy358 on July 27, 2008, 09:49:15 pm
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For our extended experimental we looked at equilibria and all that.
Just wondering if someone could help me out with spotting the sources of error possible here. I didn't pick up much =/
(Sorry the method's kinda of sketchy. I tried to Google it but the pracs weren't as simplistic as the one we did at school. +I'm tired =P. If it needs more detail let me know.)
Experiment 1.
[Co(H2O)6]2+ + Cl- = [CoCl4]2- + H2O
- [Co(H2O)6]2+(s) and HCl(aq) are mixed in a beaker. Stir.
- The resulting solution is poured into two test tubes.
- One test tube is placed in an ice bath, the other in a beaker with hot water.
- Watch for a reaction.
Experiment 2.
Fe3+ + SCN-(aq) = [Fe(SCN)]2+
- Make up a solution of Fe3+ and SCN-.
- Pour into test tubes.
- To each test tube add: ferric chloride; potassium thiocynate; NaF or AgNO3
- Watch for a reaction.
Experiment 3.
2NO2 = N2O4
This one was set up for us. All we had to do was go to the fume cupboard/hood, put on gloves & place pressure on the syringe or reduce pressure. Then note observations.
So, sources of error
- Temperature not being constant in experiments 2/3 - affecting rate of reaction
- Precision when making up solutions - concentrations need to be relatively accurate so colours are
- for #3, gas escaping? screws with colour intensity.
- #3, not applying pressure/reducing pressure quick enough. (kind of stupid though 'cause we could always try again if we hadn't noticed a change)
Any others? =S
ty =]