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Define Lattic Enthalpy
The enthalpy change that accompanies the formation of one mole of ionic compound from its gaseous ions under standard conditions
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Define Hess' law
States that if a reaction occurs by more than one route and the initial and final conditiions are the same, the total enthalpy change is the same for each route
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Define The standard enthalpy change of formation.
The enthalpy change that takes place when one mole of a compound is formed from its consituent elements in their standard states under standard conditions
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Define enthalpy change of atomisation
The enthalpy change that takes place when one mole of gaseous atoms forms from the element in its standard state.
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Define first ionisaion enery
the enthalpy change accompanying the removal of one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions
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Define second ionisation energy
the enthalpy change accompanying the removal of one electron from each ion in one mole of gaseous 1+ ions to form one mole gaseous 2+ ions
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Define first electron affinity
the enthalpy change that accompanies the addition of one electron to each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1- ions
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Define second electron affinity
the enthalpy change that accompanies the addition of one electron to each ion in one mole of gaseous 1- ions to form one mole of gaseous 2- ions
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Is lattice enthalpy exo- or endothermic?
Exothermic
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Why is lattice enthalpy exothermic?
More energy is given out during the forming of the ionic bonds than is taken in during the breaking of the ionic bonds
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What does lattice enthalpy indicate?
The strength of an ionic lattic and is a measure of the ionic bond strength. The larger the negative value, the stronger the electrostatic forces of attraction between the oppositely charged ions of the lattice
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Does a covalent structure have a lattice enthalpy?
No. There are no oppositely charged ions in a covalent structure
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True or false; Lattice enthalpies can not be measured directly
True
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Define: Standard enthalpy change of solution.
The enthalpy change that takes place when one mole of compound is dissolved in water under standard conditions
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Define: Standard enthalpy change of hydration
The enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water forming one mole of aqueous ions under standard conditions
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Define: Entropy
Entropy, S, is the quantative measure of the degree of disorder in a chemical system
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Does entropy increase or decrease with disorder?
Increase
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Define: Free energy change
The balance between enthalpy, entropy and temperature for a process: (delta G)= (delta H)-T(in kelvin)(Delta S). A process can take place spontaneously when (Delta G)
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What are the conditions for an endothermic reaction so it can take place spontaneously?
Delta S must be positive. The temperature must be high enough so that TxDelta S> Delta H
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Other cards in this set

Card 2

Front

Define Hess' law

Back

States that if a reaction occurs by more than one route and the initial and final conditiions are the same, the total enthalpy change is the same for each route

Card 3

Front

Define The standard enthalpy change of formation.

Back

Preview of the front of card 3

Card 4

Front

Define enthalpy change of atomisation

Back

Preview of the front of card 4

Card 5

Front

Define first ionisaion enery

Back

Preview of the front of card 5
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