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    I don't understand why the enthalpy change of hydration is more exothermic the smaller the ion. When they're in an ionic lattice I understand why the bonds are stronger (because they can pack closer together), but I don't understand it for this. Something else that is confusing me is- in my book it says 'small ions exert more attraction on water molecules and more energy is released'. How can the size of an ion cause it to attract other molecules more strongly? It just doesn't make sense to me :confused:
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    Smaller ions have a higher charge density, which means that it will attract other molecules more strongly.
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    (Original post by Holby_fanatic)
    Smaller ions have a higher charge density, which means that it will attract other molecules more strongly.
    I googled charge density and it said 'in electromagnetism, charge density is a measure of the electric charge per unit volume of space, in one, two or three dimensions. More specifically: the linear, surface or volume charge density is the amount of electric charge per unit length, surface area or volume'. But I don't seem to understand this concept, so just because a charge is in a smaller volume it's stronger? I don't get how this works.

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    (Original post by tammie123)
    I googled charge density and it said 'in electromagnetism, charge density is a measure of the electric charge per unit volume of space, in one, two or three dimensions. More specifically: the linear, surface or volume charge density is the amount of electric charge per unit length, surface area or volume'. But I don't seem to understand this concept, so just because a charge is in a smaller volume it's stronger? I don't get how this works.

    The smaller the ion, the closer the electrons are to the positively charged nucleus and that gives it a higher charge density.
    Smaller ions give more exothermic values because they can get closer to one another.
 
 
 
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