enthalpy of hydration alevel chem question
For two factors that affect enthalpy change of hydration, the answers are ionic charge and ionic radius. I was thinking like polarity so water molecule's can join up easily or more difficulty and there are intermolecular bonds it has as you have to break the bonds, why are these incorrect and not right for OCR A chemistry alevel?
Thank you
Thank you
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by LisaPereraFor two factors that affect enthalpy change of hydration, the answers are ionic charge and ionic radius. I was thinking like polarity so water molecule's can join up easily or more difficulty and there are intermolecular bonds it has as you have to break the bonds, why are these incorrect and not right for OCR A chemistry alevel?
Thank you
Thank you
The more charge dense the ion is, the stronger the interactions the ion has with the dipoles in the surrounding water molecules, leading to a hydration process that is more exothermic.
Charge density is the ratio of the charge of the ion to its volume, hence it depends on both the charge and radius of the ion.
Polarity isn’t something I’d discuss. Firstly, the polarity of the water molecules that do not end up bound to the ion upon hydration do not become more or less polar. Secondly, gaseous ions aren’t something you can truly describe as polar - being monatomic, they don’t have a positive end and a negative end - they are either positive or negative. Granted, upon the formation of a complex with water ligands you have a phenomenon called polarisation, it’s entirely irrelevant here and beyond the scope of the OCR syllabus.
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