NEETChemistryd and f Block Elements
Three different oxides of chromium, X, Y, and Z, exhibit the following properties: Oxide X dissolves only in dilute acids. Oxide Y dissolves in both acids and alkalies. Oxide Z dissolves in water to give a strongly acidic solution. The oxidation states of chromium in the oxides X, Y, and Z respectively are:
Options
- A+6, +3, +2
- B+3, +4, +6
- C+2, +6, +3
- D+2, +3, +6
Correct answer
D. +2, +3, +6
Step-by-step solution
The acid-base character of transition metal oxides depends on the oxidation state of the metal. Lower oxidation states form basic oxides, intermediate states form amphoteric oxides, and higher oxidation states form acidic oxides. Oxide X dissolves only in dilute acids, which indicates it is a basic oxide. For chromium, the basic oxide is CrO , where the oxidation state of chromium is +2 . Oxide Y dissolves in both acids and alkalies, indicating it is an amphoteric oxide. The amphoteric oxide of chromium is Cr₂O₃ ,