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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Electrolysis of solutions
Electrolysis uses electricity (energy) to drive a non-spontaneous reaction which is useful for recharging batteries, splitting water to make hydrogen
The chemistry of fuel cells
Fuel cells commonly use the reaction between hydrogen and oxygen to produce a voltage, with water being the only waste
The chemistry of batteries
Modern storage cells (batteries) can be divided into the non-rechargeable kind (primary cells) and the rechargeable kind (secondary cells). Primary
Using the relationship between potential difference and Gibbs energy to calculate a value for the equilibrium constant, K
Ecell⦵ (the maximum potential difference between two half cells) is measured when the reactants are under standard conditions (1.00 mol
Understanding the relationship between the potential difference for an electrochemical cell and Gibbs energy
The spontaneity or feasibility of a reaction can be described by both a positive Ecell⦵ value or a negative value
The chemistry of corrosion
The rusting of iron can be summarised by the equation 4 Fe(s) + 3 O2(g) + H2O(l) ⇾ 2 Fe2O3•xH2O(s)
Predicting the feasibility of redox reactions using standard electrode potentials
A redox reaction consists of two half reactions – an oxidation and a reduction reaction. If we take a pair
Continue readingPredicting the feasibility of redox reactions using standard electrode potentials
Determining the potential difference of an electrochemical cell
We can link any two half cells together to form an electrochemical cell. A high resistance voltmeter prevents current (electrons)
Continue readingDetermining the potential difference of an electrochemical cell
What is an electrode potential?
If we place a strip of a metal such as zinc into a beaker containing zinc sulphate (the electrolyte) an
Using oxidation states to balance half equations
Often writing a half equation to show reduction or oxidation is straight forward – all we need to do is
Continue readingUsing oxidation states to balance half equations