(Solved): Need Help! Q3. Compare the IR spectra of [Co(NH3)6]Cl3 (Fig 1) with [Co(NH3)5Cl3Cl2 ...

Q3. Compare the IR spectra of $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]\mathrm{Cl}3$ (Fig 1) with $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5{\mathrm{Cl}}_3{\mathrm{Cl}}_2$ ( ${\mathrm{Fig}}_2$ ). Explain the main difference. Is this consistent with the structure of $[\mathrm{Co}(\mathrm{NH}){)}_3{\mathrm{Cl}}_3{\mathrm{Cl}}_2$ ? Fig 1 Fig 2 Q4. The UV-Vis spectra of $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]\mathrm{Cb}$ (Fig 3) and $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_3{\mathrm{Cl}}_{\mathrm{C}}{\mathrm{Cl}}_2$ (Fie $4\mathrm{N}\dots$ compounds' colors are shown below: What is ${?}_{\max }$ in the visible spectrum for both compounds? Would you expect them to be the same or different? Why? Q6. The spectrochemical series arranges ligands in order of their ability to split d-orbitals in octahedral coordination compounds and shown on the following page: ${\mathrm{I}}^{?}<{\mathrm{Br}}^{?}<{\mathrm{S}}^{2?}<{\mathrm{Cl}}^{?}<{\mathrm{F}}^{?}<{\mathrm{OH}}^{?}<{\mathrm{H}}_2\mathrm{O}<{\mathrm{SCN}}^{?}<{\mathrm{NH}}_3<{\mathrm{CN}}^{?}$ Increasing splitting of d-orbitals The greater the splitting, the greater the energy difference $(?E)$ between the sets of $d$ orbitals. So ${\mathrm{Cl}}^{?}$causes less splitting (and lower $?$ ) than ${\mathrm{NH}}_3$. Also recall $\mathrm{E}=\mathrm{h}/?$ Comparing the ${?}_{\max }$ values for $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$ and $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5{\mathrm{Cl}}_{\mathrm{C}}{\mathrm{Cl}}_2$ in the visible region, explain why replacing one of the ${\mathrm{NH}}_3$ ligands with a $\mathrm{Cl}$ ligand shifts the ${?}_{\max }$ for $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Cl}\right]{\mathrm{Cl}}_2$ ?