Monday, May 01, 2006
AP: chromate to dichromate equilibrium
Here is the link from class today:
Remember, the reaction is
2H+ + 2 CrO4 2- (yellow) --> Cr2O7 2- (orange) + H2O
http://www.chem.uiuc.edu/webFunChem/chromate/ChromateIndex.htm>
and, for another color equilibrium, recall our redox titration:
MnO4 - (purple) + H2O2 --> Mn 2+ (colorless) + O2 + H2O
so the endpoint occurs when the solution in the flask stays pinkish (between colorless and purple)...permanganate acts as its OWN indicator because it is a colored ion.
Remember, the reaction is
2H+ + 2 CrO4 2- (yellow) --> Cr2O7 2- (orange) + H2O
http://www.chem.uiuc.edu/webFunChem/chromate/ChromateIndex.htm>
and, for another color equilibrium, recall our redox titration:
MnO4 - (purple) + H2O2 --> Mn 2+ (colorless) + O2 + H2O
so the endpoint occurs when the solution in the flask stays pinkish (between colorless and purple)...permanganate acts as its OWN indicator because it is a colored ion.
# posted by C @ 10:22 AM 
