The complex anion in Ba₂[Cr(CN)6] is a tetragonally distorted octahedral complex (Dan). Baz[Cr(CN)6] is paramagnetic at room temperature with S = 1. Assume that the complex is a low-spin complex. a) Identify if the [Cr(CN)6] anionic complex has 4 long and 2 short bonds (left side of figure) or if the complex has 4 short and 2 long bonds (right side of figure) with respect to Oh symmetry. Use crystal field theory to answer this question. Explain/rationalize your decision. Can the provided information decide on the order of orbital energies? Dah Tetragonal Distortion ய Dab z-compression z-elongation x and y elongation O symmetry x and y compression E eg d² dx²-y² t2g dxy dxz dyz Question 4 a) continued: Provide your explanations in the space below. b) At low temperatures Ba₂[Cr(CN)6] is ferromagnetically ordered with a phase transition to a paramagnetic phase at Tc = 150K. Sketch the magnetic susceptibility vs. temperature in the diagram below. Indicate Tc as well as the paramagnetic and ferromagnetic regions in that diagram. Identify in what temperature range the magnetic moments are static or dynamic. - X (emu/mol) 0 0 50 100 150 200 250 300 T (K) c) You dissolve Baz[Cr(CN)6] in aqueous hydrofluoric acid and crystallize Baz[CrF6] from that solution. Upon heating to 980 K the crystalline Ba2[CrF6] coordination compound decomposes into barium fluoride and chromium fluoride while maintaining the original oxidation states. Write a balanced equation for the decomposition reaction. PIC COLLAGE d) The chromium fluoride (formed in question 4c)) is a blue-green solid that crystallizes in the rutile structure. Explain the origin of the blue-green color. e) The chromium fluoride undergoes (in the absence of O2) hydrolysis in water, forming the corresponding chromium hydroxide and hydrofluoric acid. Write down a balanced hydrolysis reaction. CrO2 is a paramagnetic black solid with a rutile structure. Heating 0.9461 gram of CrO2 in air to 1200 K results in a mass loss of 9.52%. What is the product of this reaction? g) Cr304 has never been reported as a spinel structure Cr²+(Cr3+)204 (in accordance to the spinel mineral MgAl204). Predict if Cr304 is expected to form a 'normal' spinel or an 'inverse' spinel if a Cr304 spinel phase will ever be prepared.