资源简介

(共22张PPT)
Group VIA
O S Se Te Po
Oxygen, Sulfur, Selenium, Tellurium, Polonium
95kJ/mol energy required
or: photosensitizer
158kJ/mol energy required,
LESS LIKELY
Trioxygen (ozone)
3 O2(g) 2 O3(g) @ 10~20 kV electric field
Tetrahedral
Trigonal planar
delocalized p-bonding with Hg2+
Oxides
H2O2 is a clear, colorless liquid which is miscible with water in all proportions
Decomposition
takes place in the presence of small amounts of catalyst even in aqueous solution. In the absence of catalyst, it occurs only in the gas phase at high temperature.
Hydrogen peroxide is weakly acidic in aqueous solution, with a dissociation constant of 1.78 × 10–12 (pK 11.75) at 20 °C. As a weak acid, hydrogen peroxide forms salts with various metals.
Hydrogen peroxide can behave both as an oxidizing and as a reducing agent.
Systems with a redox potential E0 <– 1.80 V at pH 0 cannot be oxidized
systems with a redox potential E0 > – 0.66 V at this pH cannot be reduced
Production
1. Anthraquinone Process
2. Propanol Process
aldehyde
ketone
3. Electrochemical Processes
The basis of electrochemical processes is anodic oxidative coupling of sulfate ions to peroxodisulfate ions
Production of hydrogen peroxide from peroxy compounds
BaO2
Na2O2
(CH3)3CO–OH
cyclooctasulfur
159 oC, & 104 fold increase in viscosity
mp 119 oC
mp

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