Transition Metal Complexes Assessment Question 24 Which of the following is not an isomer of the complex shown below of formula [CoBr₂CI(NH3)3] Br Br.. CI Co H3N NH3 a. NH3 b. C. d. e. BP.. NH3 Co H&N NH3 CI Ch. Br HaN CO Br Br NH3 All of these are HN CI Co BCI isomers NH3 NH3 H&N NH3 Br Co H&N Br NH3 Br

Which of the following statement(s) is( are) true? a. The coordination number of a metal ion in an octahedral complex ion is 8. b. All tetrahedral complex ions are low-spin. c. The formula for triaquatrianuninechromiwn(III) sulfate is [Cr(H2O)3(NH3)](SO4)3. d. The electron configuration of Hf2+ is [Xe]4f126s2. e. Hemoglobin contains Fe3+.

Ammonia and potassium iodide solutions are added to an aqueous solution of Cr(NO3)3. A solid is isolated (compound A), and the following data are collected: i. When 0.105 g of compound A was strongly heated in excess 0 2, 0.0203 g CrO3 was formed. ii. In a second experiment it took 32.93 mL of 0.100 M HCI to titrate completely the NH3 present in 0.341 g compound A. iii. Compound A was found to contain 73.53% iodine by mass. iv. The freezing point of water was lowered by 0.64C when 0.601 g compound A was dissolved in 10.00 g H2O (Kf =1.86Ckg/mol). What is the formula of the compound? What is the structure of the complex ion present? (Hints: Cr3+ is expected to be sixcoordinate, with NH3 and possibly I as ligands. The I ions will be the counterions if needed.)

a. In the absorption spectrum of the complex ion Cr(NCS)63, there is a band corresponding to the absorption of a photon of light with an energy of 1.75 104 cm-1. Given 1 cm1 = 1.986 1023 J, what is the wavelength of this photon? b. The CrNC bond angle in Cr(NCS)63 is predicted to be 180. What is the hybridization of the N atom in the Ncs- ligand when a Lewis acid-base reaction occurs between Cr3+ and NCs- that would give a 180 CrNC bond angle? Cr(NCS)63 undergoes substitution by ethylenediamine (en) according to the equation Cr(NCS)63+2enCr(NCS)2(en)2++4NCS Does Cr(NCS)2(en)2+ exhibit geometric isomerism? Does Cr(NCS)2(en)2+ exhibit optical isomerism?