Enthalpy and Entropy

Factors Affecting Hydration Enthalpies

Factors Affecting Hydration Enthalpies: Hydration enthalpies affected by ionic size and ionic charge in same way as lattice enthalpy.  Effect of Ionic Size: Ionic size increase down a group. - MN+ is has a smaller ionic radius than Y+. - Attraction between ion and...

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Entropy

Entropy: The greater the entropy, the greater the disorder. Units of entropy are JK-1mol-1 . 0K = no energy so minimum disorder.  States of Matter: Generally changing from solids -> liquids -> gas by melting and boiling, increases entropy increase in disorder,...

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Free Energy

Feasibility: Reaction can only occur if products have lower overall energy than reactants, then feasible or spontaneous.  Gibbs’ Equation: The overall change during chemical reaction called free energy change- ∆G. Enthalpy change refers to heat transfer between...

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Lattice Enthalpy

Giant Ionic Compounds: Giant ionic compounds have strong ionic bonds- electrostatic attractions between oppositely- charged ions. Must overcome to melt.  Lattice Enthalpy: Lattice enthalpy is the enthalpy change that accompanies formation of one mole of an ionic...

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Factors Affecting Lattice Enthalpy

Factors Affecting Lattice Enthalpy:  Add up ionic radius/ charge if given a range of elements and compounds. When ions in two different groups, need to talk about both ionic charge and ionic size e.g. Mg2+ and Na+.  Don’t write Na, write Na+. Don’t forget the...

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