Calculations for AS and A level Chemistry
Being confident in tackling different types of mole calculation is the foundation upon which much of A level chemistry stands
From the blog
Why are ionic compounds soluble? (part 1)
Quick answer? It’s all about competing strengths of attraction between ions, between ions and water molecules, between water molecules themselves
Born-Haber cycles
Born-Haber cycles are simply a fancy Hess cycle transposed onto an energy level diagram and we can use them to
A note on the nature of ionic lattices
We are all familiar with the classic picture of an ionic lattice – for example, for a compound such as
What is Gibbs free energy?
The change in Gibbs free energy, ΔG, is a convenient way to determine whether a reaction is spontaneous or feasible
How to determine the temperature at which a reaction is feasible
A spontaneous or feasible process must be accompanied by a positive change in total entropy (entropy of the universe). Whether
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Understanding entropy
Why does water freeze when you place it in a freezer? Certainly not because the freezer sucks the heat out
Elimination reactions in halogenoalkanes
Halogenoalkanes undergo substitution reactions in the presence of a nucleophile such as the hydroxide ion, OH–, but most good nucleophiles
Explaining the reactivity of halogenoalkanes
Can we predict the trend in reactivity of fluoromethane, chloromethane, bromomethane and iodomethane based on any of the information below?
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Nucleophilic substitution in halogenoalkanes
Halogenoalkanes react with nucleophiles in nucleophilic substitution reactions. The halogen atom in the molecule is replaced by the nucleophile and
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Titration – experimental technique questions
Questions based on carrying out titration and interpreting the results are common both at AS and A level. Before we
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