JEE MainChemistryClassification of Elements and Periodicity in Properties
The first ionization enthalpy ( _i H₁ ) and electronegativity ( EN ) values for two hypothetical main-group elements X and Y are given below: Element X : _i H₁ = 419 kJ mol ⁻¹ , EN = 0.8 Element Y : _i H₁ = 1256 kJ mol ⁻¹ , EN = 3.0 Based on the given data, identify the correct statement regarding the nature of the oxides formed by X and Y , and the predominant nature of the bond in the compound XY .
Options
- AThe oxide of X is acidic, the oxide of Y is basic, and the compound XY is predominantly covalent.
- BThe oxide of X is basic, the oxide of Y is acidic, and the compound XY is predominantly ionic.
- CThe oxide of X is basic, the oxide of Y is acidic, and the compound XY is predominantly covalent.
- DThe oxide of X is acidic, the oxide of Y is basic, and the compound XY is predominantly ionic.
Correct answer
B. The oxide of X is basic, the oxide of Y is acidic, and the compound XY is predominantly ionic.
Step-by-step solution
Element X has a low first ionization enthalpy and a low electronegativity, which are characteristic properties of a highly reactive metal (such as an alkali metal). Metals generally form basic oxides. Element Y has a high first ionization enthalpy and a high electronegativity, which are characteristic properties of a non-metal (such as a halogen). Non-metals generally form acidic oxides. The electronegativity difference between Y and X is 3.0 - 0.8 = 2.2 . A large electronegativity difference (typically greater tha