chem whatarethemechanismsofchemicalchange
Reactivity 3.1.12 - the pH of a salt solution depends on the relative strengths of the parent acid and base
see 3.1.10 and 3.1.11 acid and base dissociation constants (HL)
the salt formed in a neutralisation reaction is an ionic compound:
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the cation is the conjugate acid of the parent base
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the anion is the conjugate base from the parent acid
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neutralisation reactions do not all form neutral aqueous solutions
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the
of a salt solution depends on whether and to what extent their ions react with water and hydrolyse it - releasing or ions
the relative strengths of the conjugate acids and bases in the salt determine the extent of hydrolysis reactions
salt of strong acid and strong base - no hydrolysis
the conjugate acid and the conjugate base are both weak, so there is virtually no hydrolysis of ions, and the
salt of weak acid and strong base - anion hydrolysis
this is because the conjugate base of
salt of strong acid and weak base - cation hydrolysis
this is because the conjugate acid of the weak base
salt of weak acid and weak base
the salt formed has relatively strong conjugates and both carry out hydrolysis. the
challenge questions
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formulate equations for reactions that produce the salt ammonium nitrate from its parent acid and base and deduce the
of its solution. at high temperatures, solid
decomposes to produce nitrogen, oxygen and water. formulate equations for this reaction and suggest why it can be explosive.
2 moles of solid releases 7 moles of gas, causes rapid expansion and increase in pressure.