Master the Toughest OCR A-Level Chemistry Topics Before Exam Day

This topic is almost always the “opener” question in OCR A-Level exams.

Highly important takeaways we’ll cover:

• Subatomic particles

• Successive ionisation energies

• Electron shells and shielding

• Periodicity across periods

This topic is foundational across the A-Level syllabus, and you’ll need to be savvy in using mole calculations across various topics.

Highly important takeaways we’ll cover:

• Mole calculations

• Empirical and molecular formulae

• Ideal gas equation

• Titration calculations

Enthalpy Changes - one of those that trips students up, but when mastered, translates to sure marks.

Highly important takeaways we’ll cover:

• ΔH definitions (formation, combustion…)

• Bond enthalpies

• Hess cycles

• Calorimetry (q = mcΔT)

How Fast? is another topic that always gets a seat in the exams.

Highly important takeaways we’ll cover:

• Rate equations

• Orders of reactants and overall order

• Rate constant (k) and unit derivation

• Factors affecting rate of reaction

Very commonly examined, you’ll become comfortable with which way the equilibrium lies with changes.

Highly important take-aways we’'ll cover:

• Kc and Kp calculations

• Le Chatelier’s Principle

• Factors that affect equilibrium position

Organic Mechanisms may not be a topic in and of itself, but it is the bedrock of several organic topics.

In part one, we’ll cover:

• Reactions of alkanes, alkenes and haloalkanes

• Curly arrow mechanisms

• Reaction conditions and reagents

Organic Mechanisms may not be a topic in and of itself, but it is the bedrock of several organic topics.

In part two, we’ll cover:

• Reactions of benzene, carbonyls and alcohols

• Curly arrow mechanisms

• Reaction conditions and reagents

Usually one of the final topics to be examined in A-Level Chemistry exams and one of the most mark-fetching.

Highly important takeaways:

• Empirical formulae

• Common IR peaks

• How to interpret MS

• NMR chemical shifts and splitting

Acids, Bases & Buffers

Acids and bases show up every single year — and once you understand how equilibrium ties everything together, this topic becomes one of the most reliable places to secure marks.

What it’s about:
How acids and bases behave, how to calculate pH, and how buffer systems resist changes in pH.

You need to know:

• Definitions of acids, bases and conjugate pairs

• Strong vs weak acids

• pH calculations

• Ka, pKa and using the acid dissociation expression

• Buffer solutions and how they maintain pH

• Buffer and titration calculations

Transition metals can look intimidating at first, but once you get the hang of the colour changes and complex ions, this topic becomes one of the easiest places to pick up marks.

What it’s about: Properties and reactions of d-block elements.

We’ll be looking at:

• Various oxidation states of metal complexes

• Ligand substitution reactions

• Colour changes and precipitation

General exam past paper practice on AS Paper 1 questions.

Coming soon!