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Write the favourable factors for the formatJon of ionic bond. |
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Answer» Solution :The easy of formation of the POSITIVE and negative ions from the respective neutral atoms. The arrangement of the positive and negative ions in the solid, that is, the lattice of the crystalline compound. `M_((g)) RARR M_((g))^(+) + e^(-)` .... Ionization enthalpy`(Delta_(i) H)` `X_((g)) + e^(-) rarr X_((g))`.... electron gain enthalpy `(Delta_(eg)H)` Obviously Ionic bonds will be formed more easily between elements with comparatively low ionization enthalpies and elements with comparatively high negative value of electron gain enthalpy. And there will be for are lattice energy (enthalpy) `(Delta_(L)H)` of crystal.`M_((g))^(+) + X_((g))^(-) rarr MX_((s))` The ionization enthalpy `(Delta_(i) H)` is always endothermic. Electron gain enthalpy `(Delta_(eg))` process may be exothermic or endothermic. And lattice enthalpy `(Delta_(L)H)` always endothermic. Ionic compounds in the crystalline state consist of orderly three - dimensional arrangements of cations and anions held together by coulombic interaction energies. These compounds crystallise in different crystal STRUCTURES determined by the size of the ions, their packing arrangements and other factors. In ionic SOLIDS, the sum of the electron gain enthalpy and the ionization enthalpy may be positive but still the crystal structure gets stabilized due to the energy released in the formation of the crystal lattice. |
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