Vanadium »
Chemical Properties »
Oxalo-vanadates »
Oxalo-vanadates
These compounds are obtained in large yellow prisms (side by side with red polyvanadates) by the action of vanadium pentoxide on boiling solutions of alkali oxalates, or by the action of normal alkali vanadates on acid oxalates. They have the general formula 3R•2O.V2O5.4C2O3.xH2O or 
, i.e. they can be looked upon as derivatives of orthovanadic acid, H3VO4. The ammonium, sodium, potassium and barium salts have been prepared. On being boiled with vanadium pentoxide these salts give rise to the oxalo-molybdovanadates, which also form bright yellow crystals. Those which separate most easily have the compositions:
2R•2.V2O5.2C2O3.2MoO3.xH2O (RNH4 or K.)
and
3R•2.V2O5.2C2O3.6MoO3.xH2O. (R = NH4, Na, K or ½Ba.)
These are most probably derivatives of the oxalo-vanadates in which co-ordinative oxygen atoms have undergone substitution by (MoO4)'' groups. Hence they are alternatively represented as
and 
respectively.
, i.e. they can be looked upon as derivatives of orthovanadic acid, H3VO4. The ammonium, sodium, potassium and barium salts have been prepared. On being boiled with vanadium pentoxide these salts give rise to the oxalo-molybdovanadates, which also form bright yellow crystals. Those which separate most easily have the compositions: 2R•2.V2O5.2C2O3.2MoO3.xH2O (RNH4 or K.)
and
3R•2.V2O5.2C2O3.6MoO3.xH2O. (R = NH4, Na, K or ½Ba.)
These are most probably derivatives of the oxalo-vanadates in which co-ordinative oxygen atoms have undergone substitution by (MoO4)'' groups. Hence they are alternatively represented as
and respectively.
Last articles
As in 1VHDAs in 1WCK
As in 1VHO
As in 1W2K
As in 1W0Y
As in 1TAD
As in 1TND
As in 1TYE
As in 1TZA
As in 1TQL
