Week 7: Coordination Chemistry 3 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		Prelab Problems 1. A 20.0 mL sample of 0.050 M [Co(NH3)5(H2O)]3+ is titrated with 0.025 M NaOH. Calculate the concentrations of [Co(NH3)5(H2O)]3+, [Co(NH3)5(OH)]2+, H3O+, and OH- before titration begins. What volume of NaOH will be required to reach the endpoint? 2. In the titration of 40 mL of 0.025 M [Co(NH3)5(H2O)]3+ with 0.100 M NaOH, calculate the the volume of NaOH required to reach the endpoint. Calculate the concentrations of [Co(NH3)5(H2O)]3+, [Co(NH3)5(OH)]2+ and OH- at the end point 3. A 0.246 g sample of [Co(NH3)5(H2O)][NO3]3 is dissolved in 75 mL of water and titrated with 0.0962 M NaOH according to the procedure in this experiment. The end point comes at 7.21 mL. The pH when 3.60 mL base had been added was 6.20. Compare the observed end point position with that expected on the basis of the weight of complex used and its molecular formula. From this data, what is the experimental pKa of the cobalt complex?
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