SOLUTION. This coordination complex is called tetraamminechloronitrito-N-cobalt (III). N comes before the O in the symbol for the nitrite ligand, so it is called nitrito-N. If an O came first, as in [CoCl (ONO) (NH 3) 4] +, the ligand would be called nitrito-O, yielding the name tetraamminechloronitrito-O-cobalt (III).
To find the correct oxidation state of O2 (Oxygen gas), and each element in the molecule, we use a few rules and some simple math.First, since the O2 molecul
From Rule 6, we see that the sum of the oxidation numbers in the dichromate ion Cr 2 O 7 2-must be -2. We know that the oxidation number of O is -2, so all that remains is to determine the oxidation number of Cr, which we can call y. the dichromate ion can be written as: [Cr 2 (y) O 7 (2-)] 2-so that 2(y) + 7(-2) = -2 or y = +6.
Oxidation–reduction properties. The chromate and dichromate ions are fairly strong oxidizing agents. Commonly three electrons are added to a chromium atom, reducing it to oxidation state +3. In acid solution the aquated Cr 3+ ion is produced. Cr 2 O 2− 7 + 14 H + + 6 e − → 2 Cr 3+ + 7 H 2 O ε 0 = 1.33 V
Although extensive researches have been performed on Cr(III) oxidation by H 2 O 2, previous research mainly focused on Cr(OH) 3 or Cr 3+ ions (Knoblowitz and Morrow, 1976; Rao et al., 2002), and much less is devoted to Cr(III) oxidation by H 2 O 2 from naturally occurring Cr x Fe 1–x (OH) 3 precipitates and NOM-Cr(III) colloids (Pettine et al
The crystal structure difference between CrOOH and Cr(OH) 3 leads to the different oxidation reaction between O 2 and Cr(III). The significant alteration of oxidation process in (110), (310), (321) crystal planes is also observed indicating the crystal orientation dependence. Based on the chemical reaction kinetics, the chemical equivalent
fEkaV. 174 270 36 63 203 381 464 205 39
cr oh 3 oxidation number
