Post-lab Question

15 Why did you start with a cobalt(II) salt instead of a cobalt(III) salt for your 

16 Approximately what percentage of the ammonia ends up in your compound Why do you think an excess of ammonia is used  

17 What happens to the excess hydrogen peroxide Write a balanced chemical equation to describe this process. Why is the peroxide added slowly  

18 It has been shown that, under the conditions of all three syntheses, an equilibrium is established between [Co(NH3)6]3+ and [Co(NH3)5(H20)]3+ (pAia 6.6), which rapidly becomes [Co(NH3)5(OH)]2+. The resulting equilibrium is given below  

The equilibrium position for this reaction is independent of NH3 concentration. What added reagent is used to shift the equilibrium to obtain the desired product (Hint compare all three syntheses.) 

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VIII. Conclusions and/or Post-lab Summarize in a paragraph what the laboratory data showed. Include percent error(s) if possible. This is also a good area to include any statistical work comparing your work with class averages or expected/theoretical results. Some laboratory manuals include Post-Lab questions, which would be included here. 

A meso form with any one of the enantiomers of tartaric acid represents a pair of diastereomers. Although it may not be true for this compound because of the meso form, in general, if you have n stereocenters, there are 2n stereoisomers possible (see Post-Lab question no. 3). 

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