A hydrated chromium(III) complex, A, is heated in a crucible to remove the water of crystallisation. The anhydrous complex B is formed. The results of this experiment are shown below:
The anhydrous complex B is analysed and found to have a molar mass of 338.5 g mol-1 and to contain the following percentage composition by mass:
Cr, 15.36%; C, 21.27%; N, 24.82%; H, 7.09%; Cl, 31.46% \text{Cr, } 15.36\%; \text{ C, } 21.27\%; \text{ N, } 24.82\%; \text{ H, } 7.09\%; \text{ Cl, } 31.46\% Cr, 15.36%; C, 21.27%; N, 24.82%; H, 7.09%; Cl, 31.46%The anhydrous complex B contains a cation C comprising Cr\text{Cr}Cr, C\text{C}C, N\text{N}N and H\text{H}H only.
Cation C is six-coordinate, contains three molecules of the bidentate ligand D, and exists as optical isomers.
Determine the formula of A, B, C and D and draw the 3D structures for the optical isomers of C.
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48 exam-style questions on OCR A A Level Chemistry Transition elements. Each one has a worked solution and a mark scheme showing where the marks go.