IB Chemistry

What this covers

• Structure 1–3: electron configurations and ionisation energy trends, Lewis formulas and VSEPR shapes, intermolecular forces ranked against boiling point data, metallic and ionic lattice reasoning
• Reactivity 1: enthalpy cycles using Hess's law, bond enthalpy versus formation enthalpy calculations, and (HL) Born–Haber cycles, entropy change, and ΔG = ΔH − TΔS spontaneity arguments
• Reactivity 2: rate expressions from experimental data, rate-determining steps, Kc and Kp expressions, the reaction quotient, and Le Châtelier reasoning tied to Kc values
• Reactivity 3: pH, pOH, Ka/Kb/pKa, buffer calculations, titration curve interpretation, redox half-equations, and (HL) electrolysis and voltaic cell potentials
• Organic chemistry: functional group reactions, curly-arrow mechanisms for free-radical substitution, nucleophilic substitution and electrophilic addition, plus (HL) structure determination from IR, MS and 1H NMR
• Scientific investigation skills: research question framing, controlled variables, absolute and percentage uncertainty propagation, graphing with error bars, and evaluation against the IA criteria

Where learners get stuck

Treating the data booklet as a lookup table rather than reading which quantity it actually gives

Section 12 gives bond enthalpies (average, gas phase, bonds broken minus bonds formed) while other sections give standard enthalpies of formation or combustion, each with a different sign convention and cycle direction. Students who memorised one formula apply it to the wrong data set and get the right magnitude with the wrong sign.

Saying 'the equilibrium shifts right so Kc increases' when a concentration or pressure is changed

Le Châtelier is usually taught as a shifting-arrow rule before Kc is taught as a constant. Only temperature changes Kc; everything else changes Q and the system moves back to the same Kc. The two ideas are taught weeks apart and rarely reconciled explicitly.

Reporting a calculated result to more significant figures than the least precise measurement, or quoting uncertainty in the wrong form

Calculators return long decimals, and students propagate percentage uncertainties correctly but then forget to convert back to an absolute uncertainty matching the value's final decimal place. This costs marks in the IA and in Paper 2 data questions repeatedly.

Assuming any reaction with negative ΔH is spontaneous

Enthalpy is taught first and for months is the only energy quantity available, so 'exothermic = happens' becomes the default. Entropy and the temperature term arrive later and are treated as a separate calculation rather than as the deciding factor in the same question.

What a session looks like

You talk with Evelyn by voice for roughly 30–50 minutes on one focused area — say, weak acid–strong base titration curves, or building a Born–Haber cycle for magnesium oxide. Evelyn asks you to reason through a problem aloud, interrupts when a step doesn't follow, and asks for the chemical justification rather than the numerical answer. Past-paper-style questions are worked in full with mark-scheme-style expectations for wording, units and significant figures. For IA support, sessions focus on narrowing a research question, identifying which variables are genuinely controlled, and planning uncertainty handling before data collection rather than after. You can share a spectrum, a graph or a problem set to work through together, and each session ends with a short summary of what to practise before the next one.

Helpful to know first

• Comfort with mole calculations, balancing equations, and converting between mass, moles, concentration and gas volume
• Algebraic rearrangement, work with logarithms and exponentials (needed for pH, Ka and Arrhenius-type reasoning), and reading values from graphs
• Familiarity with the periodic table and basic bonding ideas from MYP Chemistry, IGCSE, or an equivalent pre-IB course
• Access to the IB Chemistry data booklet, since almost every quantitative session uses it

Questions

Does this cover both SL and HL IB Chemistry?

Yes. Sessions follow the same Structure and Reactivity themes and extend into HL-only material — Born–Haber cycles, entropy and Gibbs energy, rate mechanisms, buffer and pH calculations, electrode potentials, transition metal chemistry, and spectroscopic structure determination — when you're taking HL.

Can Evelyn help with my Internal Assessment?

Evelyn can help you narrow a research question, check that your variables and method will produce analysable data, talk through uncertainty propagation and graphing, and discuss what a strong evaluation section addresses. Evelyn does not write any part of your IA or supply data — the work submitted must be your own, as your school's academic integrity policy requires.

Which syllabus version does this follow?

The current syllabus with first assessment in 2025, organised into Structure 1–3 and Reactivity 1–3 with the Tools and Inquiry skills running through it, rather than the older Topics 1–21 numbering.

How is this different from AP Chemistry tutoring?

The content overlaps but the assessment differs. IB sessions work to the IB data booklet, the Paper 1B data-based format, Paper 2 extended response wording, HL-only topics such as spectroscopic identification, and the scientific investigation — none of which appear in the AP course.