Coordination Chemistry 3 Part 2 Overview Getting Started Techniques Procedure FAQ Full Lab Manual Introduction & Goals Chemistry & Background Key Questions Prelab Problems Safety Procedure In Your Write-up Experiments Index ChemLab Home		FAQ Index Question 1 Does it matter if the water bath is not exactly 35°C? Why is this temperature chosen? Question 2 We are supposed to calculate the extinction coefficient of [Co(NH3)5H20]3+ at 500 nm. Shouldn't we do a Beer's Law plot to determine this? Submissions Submit a question or an answer to the FAQ Questions & Answers Question 1 Does it matter if the water bath is not exactly 35°C? Why is this temperature chosen? Professor Hair A temperature range of 35 to 40°C is suggested. Your water bath could be anywhere in this range, but the temperature should remain constant throughout the 45 minute run. This means you should monitor the temperature carefully and add hot water, as needed, to keep the temperature constant to withing a fraction of a degree. This temperature is chosen to see absorbance changes resulting from both the ligand exchange reaction and any subsequent isomerization of the ligand. Question 2 We are supposed to calculate the extinction coefficient of [Co(NH3)5H20]3+ at 500 nm. Shouldn't we do a Beer's Law plot to determine this? Professor Hair A Beer's Law plot of absorbance vs. concentration has a slope equal to the extinction coeficient times the path length. A Beer's Law plot is the best way to determine the extinction coefficient. By using one concentration, you are calculating the extinction coefficient from one point of a Beer's Law plot. This will give you a reasonable value, for your purposes this week. Submissions Submit to the FAQ You can submit either a question or an answer to a question about this week's experiment. Your submission will be mailed to the site editor, who will respond to you directly and also add your submission to the FAQ page. Having trouble with the submission procedure? Check your Kerberos installation. If you lose the FAQ Submission window it may be hidden behind another browser window.
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