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Home › IB Diploma Programme › IB Chemistry
IB CHEMISTRY
IB Chemistry tutor online for HL and SL
IB Chemistry rewards students who can count particles accurately, explain why a reaction happens and read data from an experiment. IB Learning Star offers online tutoring for the IB Diploma Chemistry course examined from 2025, for HL and SL students alike. One-on-one lessons run live on Google Meet at times that suit your time zone, and your first class is a free trial.
HL and SL
One-on-one on Google Meet
Lessons in your time zone
Free trial class
OUR METHOD
How we teach IB Chemistry
a slip in a calculation
an explanation without the reason
data read too quickly
Most lost marks in Chemistry come from three places: a slip in a calculation, an explanation that names the right idea but not the reason, and a graph or data table read too quickly. We work on all three. Lessons start from the particle picture, then move to the equation, then to a full answer in the form the markscheme rewards.
log
rate of change
× 10ⁿ
eˣ (HL)
Chemistry also uses a fair amount of maths: logarithms, rates of change, scientific notation and, at HL, exponential functions. If that is where you slow down, we fix it inside the Chemistry lesson, with the problem in front of you.
particle picture
➜
equation
➜
full answer
Our tutors are certified IBDP tutors or have completed IBDP training, at least IB Category 2 workshops, and they teach in IB schools.
This page describes the course first examined in 2025. We will update it if the IB publishes a new Chemistry guide.
THE COURSE
The IB Chemistry course: Structure and Reactivity
The course is built on one idea: structure decides reactivity, and reactivity changes structure. There are three Structure topics and three Reactivity topics. The IB recommends 150 teaching hours at Standard Level and 240 at Higher Level. Those hours include the practical programme and the scientific investigation, so the six topics share 110 hours at SL and 180 at HL.
S1
SL hours 17
HL hours 21
TOPIC
Structure 1. Models of the particulate nature of matter
WHAT IT COVERS
The nuclear atom, electron configurations, the mole, ideal gases. HL adds more on electron configurations and ionization energies.
S2
SL hours 20
HL hours 30
TOPIC
Structure 2. Models of bonding and structure
WHAT IT COVERS
Ionic, covalent and metallic bonding, and materials. HL adds resonance, hybridization and formal charge.
S3
SL hours 16
HL hours 31
TOPIC
Structure 3. Classification of matter
WHAT IT COVERS
The periodic table and functional groups. HL adds transition elements and spectroscopy: mass spectrometry, infrared and proton NMR.
R1
SL hours 12
HL hours 22
TOPIC
Reactivity 1. What drives chemical reactions?
WHAT IT COVERS
Enthalpy changes, Hess’s law, fuels. HL adds Born–Haber cycles, entropy and Gibbs energy.
R2
SL hours 21
HL hours 31
TOPIC
Reactivity 2. How much, how fast and how far?
WHAT IT COVERS
Amounts of reactants, rates of reaction, equilibrium. HL adds reaction mechanisms, rate equations and the reaction quotient.
R3
SL hours 24
HL hours 45
TOPIC
Reactivity 3. What are the mechanisms of chemical change?
WHAT IT COVERS
Acids and bases, redox, radicals, nucleophiles and electrophiles. HL adds pH curves, electrochemical cells, Lewis acids and the SN1 and SN2 mechanisms.
HL
HL students study every SL topic in more depth and add 70 hours of extra material, with the most in Reactivity 3 and Structure 3. If you are not sure which parts of a topic your level covers, tell us at the trial class and we will map it for you.
CALCULATIONS
Calculations: the mole ladder
Mole calculations sit under almost everything in Chemistry, from gas volumes to titrations to equilibrium. Students who lose marks here usually understand the idea but skip a step. We teach a ladder of four steps that every calculation follows.
Step 4. Turn moles into the quantity asked for, then check the units and the significant figures.
Step 3. Use the mole ratio from the equation.
Step 2. Turn the given quantity into moles, using n = m / M for a mass or n = cV for a solution.
Step 1. Write the balanced equation.
A worked case: magnesium and acid
How much magnesium chloride forms when 2.50 g of magnesium reacts with excess hydrochloric acid? The equation is Mg + 2HCl → MgCl₂ + H₂. Moles of Mg = 2.50 g / 24.31 g mol⁻¹ = 0.103 mol. The ratio Mg : MgCl₂ is 1 : 1, so 0.103 mol of MgCl₂ forms. Its molar mass is 24.31 + 2 × 35.45 = 95.21 g mol⁻¹, so the mass is 0.103 mol × 95.21 g mol⁻¹ = 9.79 g. The answer has three significant figures because the mass was given to three.
Mg + 2HCl → MgCl₂ + H₂
MgCl₂ FORMED
9.79 g
0.103 mol · 95.21 g mol⁻¹ · 3 s.f.
In a lesson we then change the question: a limiting reagent, a gas collected, a solution made up to a set volume. The four steps stay the same.
ORGANIC AND DATA
Organic mechanisms and data-based questions
Organic chemistry is marked on exact steps. At both levels you describe nucleophilic substitution by showing how electron pairs move, with curly arrows. At HL you also compare the SN1 mechanism of tertiary halogenoalkanes with the SN2 mechanism of primary ones, and you explain the mechanism of electrophilic addition to alkenes.
Three common mechanism mistakes
Arrows that start in the wrong place.
A curly arrow shows an electron pair moving, so it starts at a lone pair or a bond and ends where the pair arrives.
×
Missing charges and lone pairs.
A nucleophile needs its lone pair drawn, and a leaving group leaves with its pair and carries the charge.
×
A mechanism for the wrong reaction.
Naming the type of reaction first saves the whole answer.
×
Paper 1B and Paper 2 also use data. We practise reading tables and graphs, finding gradients and areas, working out uncertainties and saying what the numbers show.
ASSESSMENT
How the Chemistry papers work
There are two papers at both levels. There is no Paper 3 and there are no option topics, so older material that used them does not match this course. Calculators are permitted, and each student gets a clean copy of the IB Chemistry data booklet, which holds the periodic table, equations and data.
data booklet + calculator
PAPER
1
36%
Paper 1: 1A and 1B
Paper 1 has two parts taken together. Paper 1A is multiple choice, and no marks are taken off for a wrong choice. Paper 1B has data-based questions and questions on experimental work. At SL Paper 1 lasts 1 hour 30 minutes and is out of 55 marks (30 for 1A, 25 for 1B). At HL it lasts 2 hours and is out of 75 marks (40 for 1A, 35 for 1B). Paper 1 is worth 36% of your grade at both levels.
PAPER
2
44%
Paper 2
Paper 2 has short-answer and extended-response questions. At SL it lasts 1 hour 30 minutes and is out of 50 marks, on standard level material only. At HL it lasts 2 hours 30 minutes and is out of 90 marks, on standard level and additional higher level material. Paper 2 is worth 44% of your grade at both levels.
Paper 1 · 36%
Paper 2 · 44%
Investigation · 20%
The remaining 20% comes from the scientific investigation, which is marked by your teacher and moderated by the IB.
INTERNAL ASSESSMENT
Coaching for the Chemistry scientific investigation (IA)
The scientific investigation is worth 20% of your grade at both levels. You collect and analyse your own quantitative data to answer a research question you form yourself, and you report it in up to 3,000 words. The report is marked out of 24 on four criteria worth 6 marks each: research design, data analysis, conclusion and evaluation.
4 × 6 =
24
In lessons we help you choose a question that you can measure well with the equipment your school has, plan the method and the range of values, work out the uncertainty you will need to handle, read your draft against the criteria and sharpen the evaluation.
HOW IT WORKS
What a Chemistry lesson looks like
01
The first lesson is a diagnostic. You show us a recent paper or a topic test and we find where the marks went: a gap in the idea, a slip in the calculation or a missing explanation. After it we agree a plan around your weakest topics and your exam session.
02
Each lesson takes one topic from the particle picture to a full answer in the form the IB markscheme rewards, with the data booklet open and the units written down. You get a short set of problems to try before the next lesson. Closer to the exams we add timed sections of Paper 1B and Paper 2, with written feedback on your working.
Lessons are one-on-one on Google Meet, in your time zone.
FAQ
What Chemistry students ask us
Is HL Chemistry much harder than SL?
HL has 90 more teaching hours, longer papers and extra content in every topic. The extra material includes entropy, rate equations, electrochemical cells and spectroscopy. The core ideas are the same, so a steady plan and early help on the topics where you lose marks work at both levels.
Which Chemistry topics do students find hardest?
It varies, but calculations with several steps, organic mechanisms and equilibrium come up most often. We find your weak spots in the first lesson rather than guess.
Can I use a calculator in the Chemistry papers?
Yes, calculators are permitted in Paper 1 and Paper 2. Your school will tell you which models the IB allows.
Does the course still have Paper 3 and option topics?
No. The Chemistry course first examined in 2025 has two papers and no option topics. Check that any practice material you use matches the current course.
Can you help with Paper 1B data questions?
Yes. We practise reading tables and graphs, finding gradients and areas, and stating uncertainties in the form the markscheme expects.
Do you help with the scientific investigation?
Yes. We help with choosing a question, planning the method, reading your draft against the criteria and improving the evaluation.
Who teaches the lessons?
Your tutor is a certified IBDP tutor or has completed IBDP training, at least IB Category 2 workshops, and teaches in an IB school. We match the tutor to your course and level.
Will lessons fit my time zone?
Yes. Lessons are one-on-one on Google Meet and we plan them around your school day, wherever you are.
How do I start?
Book a free trial class. We use it to see where you are, then suggest a plan and a lesson schedule.
Start with a trial class for Chemistry
Tell us your level (SL or HL), your exam year and the topics that worry you most. We will plan the first lesson around them.
