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
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Oxidising alcohols to form a carbonyl
Primary and secondary alcohols are oxidised by common oxidising agents such as potassium manganate(VII), KMnO4, or acidified sodium dichromate(VI), Na2Cr2O7.
What makes a good leaving group?
And why do some perfectly plausible reactions just not happen? Acyl chlorides readily react with hydroxide ions to form a
How to name an alcohol, an alkoxide or an ether
Alcohols are organic molecules containing the OH, hydroxyl, functional group and are named after their parent alkane … If the
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How to prepare a halogenoalkane
There are number of ways to make a halogenoalkane, each of which has its own advantages and disadvantages. Halogenation of
Experimental methods for following the rate of a reaction
Quenching We can stop a chemical reaction in its tracks using a practical technique called quenching. There are two ways
Continue readingExperimental methods for following the rate of a reaction
What are autocatalytic reactions?
If we were to measure the change in concentration of a reactant over time and then plot a graph of
Reaction mechanisms, intermediates and the rate determining step
There are many reactions which happen as the stoichiometric (chemical) equation would suggest … e.g. the reaction between chlorine radicals
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Using the Arrhenius equation to find the activation energy for a reaction
For almost all reactions there is an energy barrier to overcome – this is known as the activation energy, Ea,
Continue readingUsing the Arrhenius equation to find the activation energy for a reaction
Differential and integrated rate equations for first order reactions
The decomposition of dinitrogen pentoxide is a first order reaction . 2N2O5(g) ⇾ 4NO2(g) + O2(g) The rate of the
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Half life and first order reactions
All first order reactions have a constant half life, t½, which means that the time taken for the concentration of