`=>` These oxides are generally formed by the reaction of metals with oxygen at high temperatures. All the metals except scandium form `color{red}(MO)` oxides which are ionic.
`=>` The highest oxidation number in the oxides, coincides with the group number and is attained in `color{red}(Sc_2O_3)` to `color{red}(Mn_2O_7)`.
● Beyond group `7`, no higher oxides of iron above `color{red}(Fe_2O_3)` are known.
● Besides the oxides, the oxocations stabilise `color{red}(V^V)` as `color{red}(VO_2^+, V^(IV))` as `color{red}(VO_2^+)` and `color{red}(Ti^(IV))` as `color{red}(TiO^(2+))`.
`=>` As the oxidation number of a metal increases, ionic character decreases.
● In the case of `color{red}(Mn)`, `color{red}(Mn_2O_7)` is a covalent green oil. Even `color{red}(CrO_3)` and `color{red}(V_2O_5)` have low melting points.
● In these higher oxides, the acidic character is predominant.
● Thus, `color{red}(Mn_2O_7)` gives `color{red}(HMnO_4)` and `color{red}(CrO_3)` gives `color{red}(H_2CrO_4)` and `color{red}(H_2Cr_2O_7)`.
● `color{red}(V_2O_5)` is, however, amphoteric though mainly acidic and it gives `color{red}(VO_3^(4–))` as well as `color{red}(VO_2^+)` salts.
● In vanadium there is gradual change from the basic `color{red}(V_2O_3)` to less basic `color{red}(V_2O_4)` and to amphoteric `color{red}(V_2O_5)`.
● `color{red}(V_2O_4)` dissolves in acids to give `color{red}(VO^(2+))` salts.
● Similarly, `color{red}(V_2O_5)` reacts with alkalies as well as acids to give `color{red}(3 VO )`− and `color{red}(4 VO^+)` respectively.
● The well characterised `color{red}(CrO)` is basic but `color{red}(Cr_2O_3)` is amphoteric.
`=>` These oxides are generally formed by the reaction of metals with oxygen at high temperatures. All the metals except scandium form `color{red}(MO)` oxides which are ionic.
`=>` The highest oxidation number in the oxides, coincides with the group number and is attained in `color{red}(Sc_2O_3)` to `color{red}(Mn_2O_7)`.
● Beyond group `7`, no higher oxides of iron above `color{red}(Fe_2O_3)` are known.
● Besides the oxides, the oxocations stabilise `color{red}(V^V)` as `color{red}(VO_2^+, V^(IV))` as `color{red}(VO_2^+)` and `color{red}(Ti^(IV))` as `color{red}(TiO^(2+))`.
`=>` As the oxidation number of a metal increases, ionic character decreases.
● In the case of `color{red}(Mn)`, `color{red}(Mn_2O_7)` is a covalent green oil. Even `color{red}(CrO_3)` and `color{red}(V_2O_5)` have low melting points.
● In these higher oxides, the acidic character is predominant.
● Thus, `color{red}(Mn_2O_7)` gives `color{red}(HMnO_4)` and `color{red}(CrO_3)` gives `color{red}(H_2CrO_4)` and `color{red}(H_2Cr_2O_7)`.
● `color{red}(V_2O_5)` is, however, amphoteric though mainly acidic and it gives `color{red}(VO_3^(4–))` as well as `color{red}(VO_2^+)` salts.
● In vanadium there is gradual change from the basic `color{red}(V_2O_3)` to less basic `color{red}(V_2O_4)` and to amphoteric `color{red}(V_2O_5)`.
● `color{red}(V_2O_4)` dissolves in acids to give `color{red}(VO^(2+))` salts.
● Similarly, `color{red}(V_2O_5)` reacts with alkalies as well as acids to give `color{red}(3 VO )`− and `color{red}(4 VO^+)` respectively.
● The well characterised `color{red}(CrO)` is basic but `color{red}(Cr_2O_3)` is amphoteric.