Correlation between standard enthalpy of formation, structural parameters and ionicity for alkali halides

Journal of the Serbian Chemical Society

关键词: Thermodynamic properties;    exothermicity;    interionic distance;    radius ratio;    interrelation;   

DOI  :  10.2298/JSC120113049N

来源: DOAJ

【 摘 要 】

The standard enthalpy of formation (ΔHo) has been considered to be aninteresting and useful parameter for the correlation of various properties ofalkali halides. The interrelation between ΔHo and structural parameters forthe halides of Li, Na, K and Rb has been thoroughly analyzed. When cationiccomponent element is kept constant in a homologous series of alkali halides,the negative value of ΔHo has been observed to decrease linearly withincrease of interionic distance (d) and accordingly following empiricalequation ΔHo = α + βd (where α and β are empirical constants) has beenestablished. However, for common anionic series of alkali halides an oppositenonlinear trend has been observed with the exception of common fluorides. Thecorrelation study on the standard enthalpy of formation has been extended interm of radius ratio and also discussed in the light of ionization energy ofthe metal, electron affinity of the halogen, size of the ions, ioniccharacter of bond and lattice energy of the compound.

【 授权许可】

Unknown