OCR A level Chemistry: Aromatic Compounds is apart of the Module 6: Organic Chemistry and Analysis. All presentations come with worked examples, solutions and homeworks Molecular, empirical, skeletal formula for benzene. The Kekulé model for benzene Evidence against the Kekule model The delocalised model for benzene Nomenclature for benzene rings and aromatic (arene) compounds Naming benzene containing compounds Drawing benzene containing compounds Defining an electrophile Substitution reactions Nitration of Benzene Reaction mechanisms Halogenation of Benzene Common Halogen Carriers Friedel-Crafts Alkylation Reactions Acyl Chloride Acylation Reactions of Benzene Reactivity of Alkenes and Arenes Naming phenols Distinguishing between phenols and alcohols Distinguishing between phenols and alkenes Distinguishing between phenols and carboxylic acids Phenol as a weak acid Electrophilic reactions with phenols Comparing and explaining the reactivity of phenols and benzene Naming positions on the aromatic ring Activating groups and deactivating groups 2-and-4-directing and 3-directing groups ortho-and-para directing and meta directing groups Two-step synthesis routes for benzene using directing groups. Nitration of benzene Halogenation of benzene Friedel-Crafts Alkylation of benzene

OCR A level Physics: Chapter 21 Capacitance is apart of the Module 6: Particle and Medical Physics All presentations come with worked examples, solutions and homeworks. 21.1 Capacitors 21.2 Capacitors in circuits 21.3 Energy stored by capacitors 21.4 Discharging capacitors 21.5 Charging capacitors 21.6 Uses of capacitors Electrical quantities, symbols, and units SI prefixes and standard form Definition of a capacitor Structure of a capacitor Calculating capacitance, charge, and potential difference. Uses of capacitors in circuits. Rules for capacitors in parallel (potential difference, charge, and capacitance). Rules for capacitors in series (potential difference, charge, and capacitance). Applying the rules in series and parallel. Creating a circuit to calculate the charge stored on the capacitor. Work done of a capacitor depends upon the initial potential difference and capacitance. Work done is provided by the source of potential difference. Deriving three equations for work done of a capacitor. Exponential increase and exponential decay Explaining how capacitors discharge through a resistor in parallel Definition of time constant for a capacitor Showing that time constant has units of seconds Iterative method for finding how capacitors discharge Using exponentials and logs. Solving a differential equation (needed for A-level Maths). Explaining how capacitors charge with a resistor in series Explaining how 𝑉, 𝐼, or 𝑄, change with time 𝑡 for a charging capacitor. Sketching graphs for 𝑉, 𝐼, or 𝑄, after time 𝑡 for a charging capacitor. Calculating 𝑉, 𝐼, or 𝑄, change with time 𝑡 for a charging capacitor. Calculating power output from a circuit containing a capacitor A rectifier circuit - changing an alternating input to a smooth output