Latimer Diagrams

1
Latimer Diagrams

• O, S, N Descriptive Chemistry

2

• E?Red
• ClO4- 2 H 2 e- ? ClO3- H2O 1.19
  V
• ClO3- 3 H 2 e- ? HClO2 H2O 1.21 V
• HClO2 2 H 2 e- ? HClO H2O 1.65 V
• HClO H e- ? 1/2 Cl2 (g)
  H2O 1.63 V
• 1.19 V 1.21 V 1.65 V 1.63 V
  1.36 V
• ClO4- ??? ClO3- ??? HClO2 ??? HOCl ??? Cl2 ???
  Cl-
• 1.47 V
• Reduction ???
• ??? Oxidation
• 0.36 V 0.35 V 0.65 V 0.40 V 1.36 V
• ClO4- ??? ClO3- ??? ClO2- ??? OCl- ??? Cl2 ???
  Cl-
• 0.88 V

3

• Acid 1.19 V 1.21 V 1.65 V 1.63 V
  1.36 V
• ClO4- ??? ClO3- ??? HClO2 ??? HOCl ??? Cl2 ???
  Cl-
• 1.47 V
• Basic
• 0.36 V 0.35 V 0.65 V 0.40 V 1.36
  V
• ClO4- ??? ClO3- ??? ClO2- ??? OCl- ??? Cl2 ???
  Cl-
• 0.88 V

4

• 0.36 V 0.35 V 0.65 V
  0.40 V 1.36 V
• ClO4- ??? ClO3- ??? ClO2- ??? OCl- ??? Cl2 ???
  Cl-
• 0.50 V 0.88 V

5
Disproportionation of H2O2

• 0.69 V 1.77 V
• acidic solution O2 ??? H2O2 ??? H2O
•  
• 2 H2O2 O2 2 H2O E? 1.77 0.69 1.08
  V
• H2O2 unstable

6
Sulfur

• 0.16 V 0.41 V 0.49 V 0.17 V
• SO42- ???? SO2(g) ????? S2O32- ??? S ??? H2S
• 0.54 V 0.02 V
• ????? S4O62- ?????
•  
• Basic solution
• -0.94 V -0.57 V -0.75 V -0.00
  V -0.09 V
• SO42- ??? SO32- ???? S2O32- ??? S ??? S42-
  ??? HS-
• -0.66 V -0.06 V
• Thiosulfate, S2O32-, is unstable with respect to
  disproportionation
• Thiosulfate is made by boiling S and SO32- in
  slightly basic solution
• SO2 and SO32- are good reducing agents
• S42- polysulfide ions, catenation formation of
  chains of identical atoms (esp. C)

7
Nitrogen

• Acidic solution
• 0.96 V .
• 0.79 V 1.12 V 1.00 V
  1.59 V 1.77 V 0.27 V
• NO3- ??? NO2(g) ???? HNO2 ??? NO ?? N2O ?? N2 ??
  NH4
• 1.25 V
• 5 4 3 2 1
  0 -3
•  
• NO2, NO unstable with respect to
  disproportionation
•  
• 2 NO2(g) H2O HNO2 H NO3- Dilute
  solution acid rain
• 3 NO2(g) H2O NO (g) 2
  HNO3 Synthesis of nitric acid