Full Lab Manual Introduction & Goals Chemistry & Background In
Your Write-up 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? Trustees of Dartmouth College,