variable oxidation states Flashcards
what is the most common oxidation state and why
2+
represents loss of electrons from the 4s subshell
why is
Fe3+[Ar]3d5 more stable than Fe2+[Ar]3d6
electron configurations with half filled 3d subshell are more stable than others
give the name for the ion
VO⁺₂
vanadyl (v)
give the name for the ion
VO²⁺
vanadyl (IV)
give the name for the ion
V3+
vanadium (III)
give the name for the ion
V2+
vanadium (II)
what colour is VO⁺₂
yellow
what colour is VO²⁺
blue
what colour is V3+
green
what colour is V2+
purple
what is vanadium reduced with
zinc and sulfuric acid (can be any acid)
what is vanadium oxidised with
manganate (VII) solution
what 3 things affect the redox potential for transition metal ion being reduced
- pH
- type of ligand
- conditions
(temperature, pressure, concentration)
give the equation for the redox titration between iron (II) and manganate (VII)
5Fe2+ + MnO4- + 8H+ —-> Mn2+ + 5Fe3+ + 4H2O
what are redox titration based on
redox titrations are based on change in oxidation state
what is the colour change for the redox titration between iron (II) and manganate (VII)
permanent pink due to MnO4- being present (self indicating)
write an equation for the redox titration of ethanedioate and manganate (VII)
5C2O4 2- + 2MnO4- + 16H+ —-> 10CO2 + 8H2O + 2Mn2+
what would you expect when you carry out a redox titration of ethanedioate and manganate (VII)
(2 marks)
- permanent pink due to MnO4- being present
(self indicating) - effervescence due to CO2
