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    These may seem quite obvious questions, but i can't think of the answers at the moment so here goes;

    1. Water of crystallization- if a compound is more soluble in water what will happen to the x value where M.XH20
    Where X is the number of molecules of water of crystallisation and M is the anhydrous salt.

    2. If a student tried to evaporate off the water and then add it to a pre-existing compound he already had, is his method valid or not?
    State your reasons

    3. With thermal decomposition, you are decomposing a solid although how will you know when the compound has completed its decomposition.

    If anyone could give half decent answers, i would be extremely grateful.

    Thanks
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    (Original post by amyhughesy9)
    These may seem quite obvious questions, but i can't think of the answers at the moment so here goes;

    1. Water of crystallization- if a compound is more soluble in water what will happen to the x value where M.XH20
    Where X is the number of molecules of water of crystallisation and M is the anhydrous salt.

    2. If a student tried to evaporate off the water and then add it to a pre-existing compound he already had, is his method valid or not?
    State your reasons

    3. With thermal decomposition, you are decomposing a solid although how will you know when the compound has completed its decomposition.

    If anyone could give half decent answers, i would be extremely grateful.

    Thanks
    1) compound dissolves in water due to the ion-dipole interaction between polar water molecules with the ions of compound (typically ionic) that can dissociate (partially if not entirely) in water.

    suppose if more water can interact with the anhydrous compound, do you think it'd have more water molecules in its hydrated structure? more water, does that mean more mole of water per unit formula of the hydrated compound?

    2) no idea what you want to know here, or maybe the question is incomplete?

    3) Think of examples of thermal decomposition reactions. Then from there, try to justify how can you tell whether the reaction is complete, hence no more decomposition.
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    (Original post by amyhughesy9)
    These may seem quite obvious questions, but i can't think of the answers at the moment so here goes;

    1. Water of crystallization- if a compound is more soluble in water what will happen to the x value where M.XH20
    Where X is the number of molecules of water of crystallisation and M is the anhydrous salt.

    2. If a student tried to evaporate off the water and then add it to a pre-existing compound he already had, is his method valid or not?
    State your reasons

    3. With thermal decomposition, you are decomposing a solid although how will you know when the compound has completed its decomposition.

    If anyone could give half decent answers, i would be extremely grateful.

    Thanks

    3) The most obvious example is CuSO4 when it is hydrated... If that helps?
 
 
 
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