Search results
Results from the WOW.Com Content Network
The hydrogen chromate ion, HCrO 4 −, is a weak acid: HCrO − 4 ⇌ CrO 2− 4 + H +; pK a ≈ 5.9. It is also in equilibrium with the dichromate ion: 2 HCrO − 4 ⇌ Cr 2 O 2− 7 + H 2 O. This equilibrium does not involve a change in hydrogen ion concentration, which would predict that the equilibrium is independent of pH.
Representative d-orbital splitting diagrams for square planar complexes featuring σ-donor (left) and σ+π-donor (right) ligands. A general d-orbital splitting diagram for square planar (D 4h) transition metal complexes can be derived from the general octahedral (O h) splitting diagram, in which the d z 2 and the d x 2 −y 2 orbitals are degenerate and higher in energy than the degenerate ...
Complexes which are d 8 high-spin are usually octahedral (or tetrahedral) while low-spin d 8 complexes are generally 16-electron square planar complexes. For first row transition metal complexes such as Ni 2+ and Cu + also form five-coordinate 18-electron species which vary from square pyramidal to trigonal bipyramidal.
Chromate and dichromate have equal concentrations. Setting [CrO 2− 4] equal to [Cr 2 O 2− 7] in Eq. 3 gives [CrO 2− 4] = 1 / β 2 [H +] 2 . The predominance diagram is interpreted as follows. The chromate ion is the predominant species in the region to the right of the green and blue lines. Above pH ~6.75 it is always the ...
All high-spin d 8 metal ions are octahedral (or tetrahedral), but the low-spin d 8 metal ions are all square planar. Important examples of square-planar low-spin d 8 metal Ions are Rh(I), Ir(I), Ni(II), Pd(II), and Pt(II). At picture below is shown the splitting of the d subshell in low-spin square-planar complexes. Examples are especially ...
Thus, the aquo ion is a weak acid, of comparable strength to acetic acid (pK a of about 4.8). This pK a is typical of the trivalent ions. The influence of the electronic configuration on acidity is shown by the fact that [Ru(H 2 O) 6 ] 3+ ( p K a = 2.7 ) is more acidic than [Rh(H 2 O) 6 ] 3+ ( p K a = 4 ), despite the fact that Rh(III) is ...
A V 3+ complex will have a larger Δ than a V 2+ complex for a given set of ligands, as the difference in charge density allows the ligands to be closer to a V 3+ ion than to a V 2+ ion. The smaller distance between the ligand and the metal ion results in a larger Δ, because the ligand and metal electrons are closer together and therefore ...
The phosphite ion, PO 3− 3, is a strong base, and so always carries at least one proton. In this case the proton is attached directly to the phosphorus atom with the structure HPO 2− 3. In forming this ion, the phosphite ion is behaving as a Lewis base and donating a pair of electrons to the Lewis acid, H +. Predominance diagram for chromate