A/L Chemistry 8-Unit Study Tracker

Track and master 51 A/L Chemistry lectures across 8 units with active study tasks.

Introduction

30 Second Summary

Studying for the A/L Chemistry exam can feel overwhelming when you have 178 hours of video lectures ahead of you. Without a system, it is easy to fall into passive watching and forget what you learned two weeks ago.

In this project, you will build a structured study tracker that turns 51 lecture videos across 8 units into an active learning journey. You will engage with each video through targeted objectives, note-taking prompts, and self-check tasks that prove you actually understood the material.

What You'll Build

A progress-tracked study system covering 8 core A/L Chemistry units with learning objectives, active study tasks, and unit checkpoints that keep you accountable.

By the end of this project, you'll have:

A master progress checklist covering all 51 videos across 8 units, with an exam weight map showing where the marks are.
Targeted learning objectives and active study tasks for every unit so you engage with the content instead of passively watching.
Completed unit checkpoints that test your understanding before you move on to the next topic.
Secret Mission: Build one-page cheat sheets for each unit that condense everything into exam-ready reference notes.

Do I need anything before starting?

You need your NIE Resource Book and access to YouTube. All 51 video lectures by Pasindu Balasooriya are free. You should have completed O/L Chemistry before starting.

Before We Start

Before We Start...

Set Up Your Study System

Watching 51 chemistry lectures without a plan is a recipe for passive consumption. Hours will pass, but retention will not follow.

In this step, you will build a master progress page in your notebook that tracks every video, shows where the exam marks are, and gives you a realistic completion timeline. This page becomes your motivation dashboard for the entire journey.

In this step, get ready to:

Create a master progress page with all 8 units and video checkboxes.
Write the exam weight breakdown so you know where the marks are.
Set your study pace and target completion date.

Prepare your tracking notebook

A dedicated tracker turns vague studying into visible progress. Every checked box is proof that you are moving forward.

Dedicate a fresh notebook (or a clean section of an existing one) for your chemistry tracker.
Open to the very first page. This will be your master progress page.
Write the title "A/L Chemistry Progress Tracker" at the top of the page.
List all 8 units down the left side of the page, each on its own line:

Unit 01: Atomic Structure (7 videos).
Unit 02: Structure and Bonding (6 videos).
Unit 03: Chemical Calculations (6 videos).
Unit 04: Gaseous State of Matter (5 videos).
Unit 05: Energetics (6 videos).
Unit 06: S, P and D Block Elements (8 videos).
Unit 11: Chemical Kinetics (6 videos).
Unit 12: Chemical Equilibrium (7 videos).

Next to each unit, draw empty checkboxes matching the number of videos. For example, Unit 01 gets 7 empty boxes.
Count all your checkboxes. You should have 51 in total across all 8 units.

Why a physical tracker?

Physically checking off a box after each 3.5-hour lecture creates a sense of achievement that a mental "I think I watched that" cannot match. Over 51 videos, this visual proof of progress keeps you motivated when the content gets tough.

Understand the exam weight map

Not all units are worth the same number of marks. Knowing the weight of each unit helps you decide where to invest extra revision time later.

Below your unit list on the master progress page, write the heading "Exam Weight Breakdown".
Write the approximate mark allocation for each unit:

Unit 01 (Atomic Structure): ~6.25 marks.
Unit 02 (Structure and Bonding): ~6.25 marks.
Unit 03 (Chemical Calculations): ~10 marks.
Unit 04 (Gaseous State): ~4.25 marks.
Unit 05 (Energetics): ~10 marks.
Unit 06 (S, P, D Block): ~22 marks (HIGHEST).
Unit 11 (Chemical Kinetics): ~6 marks.
Unit 12 (Chemical Equilibrium): ~18 marks (SECOND HIGHEST).

Write the total at the bottom: ~83 marks out of 150.
Circle or highlight Unit 06 and Unit 12. These two units alone are worth roughly 40 marks.

Why do Unit 06 and Unit 12 matter so much?

Unit 06 (S, P and D Block Elements) is close to one quarter of the entire paper. It is identification-based, meaning if you know the answer you get full marks, and if you do not, you get zero. There is no partial credit for showing working.

Unit 12 (Chemical Equilibrium) is roughly one fifth of the paper. It combines calculation and conceptual understanding, so you need both skills. These two units are where exam preparation time pays off the most.

Set your pace

Each video averages about 3.5 hours. Trying to binge multiple videos in one sitting leads to burnout and poor retention.

Below the exam weight section on your master page, write the heading "Study Schedule".
Write your recommended pace: 2-3 videos per week (7 to 10.5 hours of study).
Calculate your estimated completion window: 51 videos at 2 per week = 25.5 weeks, or at 3 per week = 17 weeks.
Count forward from today's date and write your target completion date on the page.
Mark weekly milestones by writing which unit and video number you aim to reach each week. For example, "Week 1: Unit 01, Videos 1-3" and "Week 2: Unit 01, Videos 4-6".

Build in buffer weeks

Add 2-3 extra weeks to your timeline for difficult units that need re-watching, school exam periods, or days when life gets in the way. A realistic schedule you can actually follow beats an ambitious one you abandon.

Which units should come first?

Follow the unit order in this project (01 through 12). Unit 03 (Chemical Calculations) is the foundation for Units 04, 05, 11, and 12. If your calculations are weak, everything that comes after will be harder.

Units 01 (Atomic Structure) and 02 (Bonding) provide the background knowledge you need for Unit 06 (Inorganic Chemistry). Skipping ahead is tempting, but the order exists for a reason.

Your study system is ready. Next up, you will dive into Unit 01 and start learning about the building blocks of chemistry: atomic structure.

Unit 01 - Atomic Structure

Your tracker notebook is set up with a master progress page, exam weight breakdown, and weekly milestones. Now it is time to fill it with actual chemistry knowledge.

Unit 01 covers atomic structure across 7 videos, roughly 24.5 hours of content. It carries approximately 6.25 marks on the exam, but the concepts here form the foundation for bonding, inorganic chemistry, and every calculation-heavy unit that follows.

In this step, get ready to:

Write learning objectives and key watch-points for all 7 videos.
Complete active study tasks after every 2-3 videos to reinforce what you watched.
Pass the unit checkpoint before moving to Unit 02.

Write your learning objectives and watch-points

Before pressing play on any video, you need a clear picture of what you are looking for. Writing learning objectives gives each video a purpose and prevents passive watching.

Open your tracker notebook to a fresh page for Unit 01.
Write Unit 01 - Atomic Structure (7 videos, ~24.5 hrs) at the top of the page.
Copy these learning objectives into your notebook. By the end of this unit, you should be able to:

Describe Dalton's, Thomson's, Rutherford's, and Bohr's atomic models and their limitations.
Explain cathode ray experiments and how the electron was discovered by J.J. Thomson.
Calculate the charge/mass ratio of the electron.
Explain Millikan's oil drop experiment and the charge of an electron.
Describe electromagnetic radiation properties including wavelength, frequency, energy, and the equation E=hv.
Explain wave-particle duality and the de Broglie equation.
Write electron configurations using quantum numbers and orbital notation.
Explain the hydrogen emission spectrum and its series.

Key watch-points for this unit

Pay close attention to HOW each atomic model was disproved. This is a common topic in MCQs.

Note the exact values: e/m ratio = 1.76 x 108 C/g (Thomson) and electron charge = 1.6 x 10-19 C (Millikan). Write these on your objectives page so you see them every time you open the unit.

Complete active study tasks after every 2-3 videos

Watching 24.5 hours of lectures without stopping to practice is a recipe for forgetting everything. These tasks force you to process what you watched before moving on.

After completing Videos 1-3:

Draw a timeline of atomic models from Democritus to Bohr.
For each model, write one sentence on what it got right and one sentence on what it got wrong.
Tick off Videos 1-3 on your master progress page.

After completing Videos 4-5:

Practice writing electron configurations for the first 36 elements.
Draw orbital diagrams for at least 10 of those elements.
Tick off Videos 4-5 on your master progress page.

After completing Videos 6-7:

Solve 5 problems involving E=hv and the de Broglie equation.
Look up the relevant section in your resource book and compare it against your notes.
Tick off Videos 6-7 on your master progress page.

Why compare with the resource book?

Pasindu sir references the NIE resource book heavily in his lectures. Comparing your notes against it helps you catch anything you missed and confirms you are using the exact terminology the exam expects.

Pass the unit checkpoint

You have now watched all 7 videos and completed the active tasks. Before moving on, you need to prove to yourself that the knowledge actually stuck.

Close your notes and answer these four questions from memory:

What experiment proved atoms are mostly empty space?
Why is the second ionization energy of sodium extremely high compared to the first?
Write the electron configuration of Fe and Fe2+.
What is the relationship between wavelength and energy?

Write your answers in your notebook under a Unit 01 Checkpoint heading.
Open your notes and check each answer against what you wrote during the videos.

What if I cannot answer all four?

That is completely normal. Identify which question tripped you up and re-watch the relevant video section. Focus only on the gap, not the entire video.

Do not move to Unit 02 until you can answer all four confidently. These concepts feed directly into bonding and electron behavior in later units.

Once you pass the checkpoint, confirm all 7 Unit 01 checkboxes are ticked on your master progress page.

Unit 01 is done. You now have a solid understanding of atomic structure, electron behavior, and the experiments that shaped modern chemistry. Next up, you will tackle Unit 02 and explore how these atoms bond together to form molecules.

Unit 02 - Structure and Bonding

Unit 01 is complete. You have a solid understanding of how atoms are structured, from electron configurations to quantum numbers.

Now the question shifts from what an atom looks like to how atoms connect with each other. Unit 02 explores the three main types of bonding and how molecular shape determines the properties of everyday substances.

In this step, get ready to:

Watch all 6 Unit 02 videos (~21 hours) and write learning objectives in your notebook.
Complete active study tasks including Lewis structures, a bonding comparison table, and resonance structures.
Pass the Unit 02 checkpoint before moving to the next unit.

Write your learning objectives and watch-points

Before you press play on the first video, set yourself up for active watching. Writing objectives beforehand gives your brain a filter for what to pay attention to.

Open a fresh page in your tracker notebook for Unit 02.
Write these learning objectives at the top of the page. By the end of this unit, you should be able to:

Explain ionic bonding, covalent bonding, and metallic bonding.
Draw Lewis structures for molecules and polyatomic ions.
Explain VSEPR theory and predict molecular shapes with bond angles.
Understand hybridization (sp, sp2, sp3).
Explain resonance structures for O3, CO2, CO3 2-, NO3-, and NO2-.
Describe intermolecular forces including van der Waals, dipole-dipole, and hydrogen bonding.
Relate bonding type to physical properties such as melting point, solubility, and conductivity.

What should I pay extra attention to?

Resonance structures are heavily tested in the exam. Practice drawing them for every example in the syllabus, not just the ones Pasindu sir shows on screen.

VSEPR shapes and bond angles are common MCQ topics. Memorize the shape names (linear, trigonal planar, tetrahedral, etc.) along with their exact angles.

Unit 02 is worth approximately 6.25 marks on the exam. The mark count is modest, but the concepts here are foundational for Unit 06 (Inorganic Chemistry), which carries 22 marks.

Complete active study tasks after each video group

Watching videos without practising is like reading a recipe without cooking. The tasks below force you to apply what you just learned, which is where real understanding forms.

After you finish Videos 1-3, complete these practice tasks:

Draw Lewis structures for at least 15 molecules and ions.
Predict the VSEPR shape for each molecule you drew.
Write the bond angle next to each shape.

Good molecules to practise with

Try a mix of simple and complex examples. Start with H2O, NH3, CH4, CO2, and BF3. Then move to polyatomic ions like SO4 2-, PO4 3-, and ClO4-. Include at least a few molecules with lone pairs on the central atom, since those are the ones that trip students up on VSEPR shape predictions.

After you finish Videos 4-6, complete these additional tasks:

Create a comparison table of ionic, covalent, and metallic bonding.
Include these four properties in the table: melting point, conductivity, solubility, and hardness.
Draw resonance structures for O3, N2O, CO2, CO3 2-, NO3-, and NO2-.
Pick 10 molecules and identify the hybridization of their central atom.
Compare your notes and diagrams against the relevant sections in your resource book.

Why does the comparison table matter?

The exam often asks you to explain differences in physical properties between substances. A side-by-side table trains you to think in contrasts. When a question asks why NaCl has a higher melting point than CCl4, you can pull the answer straight from the patterns in your table.

Tick off each video on your master progress page as you complete it.

Test yourself at the unit checkpoint

Before moving to Unit 03, you need to confirm that Unit 02 concepts are solid. Close your notebook and try to answer these four questions from memory.

Draw the Lewis structure and predict the shape of XeF4.
Explain why water has a higher boiling point than H2S.
What is the hybridization of carbon in CO2?
Draw all resonance structures of NO3-.

Can't answer all four confidently?

If you are stuck on the XeF4 question, revisit the video covering expanded octets and VSEPR for molecules with more than 4 electron pairs. Focus on how lone pairs on the central atom affect the shape.

If the boiling point comparison is unclear, re-watch the section on intermolecular forces. The key is understanding why hydrogen bonding in water is stronger than the dipole-dipole forces in H2S.

Do not move on until you can answer all four. These concepts show up repeatedly in Units 06 and 12.

Write your checkpoint answers in your notebook under Unit 02.
Confirm all 6 Unit 02 checkboxes are ticked on your master progress page.

Your bonding foundation is solid. Next up, Unit 03 covers chemical calculations. This is the unit that feeds directly into gas laws, energetics, kinetics, and equilibrium, so strong calculation skills here pay off across the rest of the syllabus.

Unit 03 - Chemical Calculations

You now have a solid grasp of how atoms bond and interact, from Lewis structures to intermolecular forces. Unit 02 gave you the language of chemical structure.

Unit 03 shifts gears entirely into pure calculation. This unit is worth approximately 10 marks on the exam, and it is the foundation that Units 04, 05, 11, and 12 all depend on.

In this step, get ready to:

Write your learning objectives and key watch-points for all 6 Unit 03 videos.
Build a formula sheet and solve at least 10 calculation problems per video from your resource book.
Pass the unit checkpoint by solving stoichiometry problems without your notes.

Write your learning objectives and watch-points

Before you press play on the first video, write the following objectives in your notebook. By the end of this unit, you should be able to:

Calculate molar mass and convert between moles, mass, and number of particles.
Balance chemical equations.
Perform stoichiometric calculations including limiting reagent, excess reagent, and yield.
Calculate concentration of solutions using molarity.
Perform dilution calculations.
Calculate empirical and molecular formulas from percentage composition.

Copy these objectives into the Unit 03 section of your notebook as a checklist you can tick off while watching.

Why is this unit different from the others?

This unit is pure calculation. Unlike Unit 01 or 02 where you learn concepts and draw diagrams, Unit 03 demands that you actively solve problems to learn anything at all. Watching alone will not build the skills you need.

Every formula and conversion factor needs to become second nature. Pay special attention to unit conversions (g to kg, cm3 to dm3) because these are where most marks are lost.

Show every step in your working

In the exam, even if your final answer is correct, you can lose marks for skipping steps. Always write out your working with units included at every stage. This habit starts now.

Write these key watch-points at the top of your Unit 03 notes page as a constant reminder while you study.

Complete active study tasks after each video

Unlike the previous two units where you did study tasks after every 2-3 videos, Unit 03 requires practice after every single video. This is the only way to build calculation fluency.

After each video, open your resource book and solve at least 10 calculation problems related to the topic you just watched.
Focus your practice on these four areas: mole conversions, balancing equations, limiting reagent problems, and solution preparation calculations.
Time yourself on each set of problems. In the exam, speed matters just as much as accuracy.

Now create a dedicated formula sheet in your notebook. This single page will become one of your most valuable revision tools.

Write the heading "Unit 03 Formula Sheet" at the top of a fresh page.
Add each formula as you encounter it in the videos. Start with the core relationships:

n = m/M (moles = mass divided by molar mass).
C = n/V (concentration = moles divided by volume in dm3).
Number of particles = n x 6.022 x 10^23 (Avogadro's number).
Continue adding dilution formulas, percentage composition formulas, and stoichiometry ratios as the videos introduce them.

Keep your formula sheet to one page

Limiting yourself to one page forces you to write only what is essential. If you need a formula often enough to be important, it earns a spot on the sheet. Everything else can stay in your detailed notes.

After you finish all 6 videos and complete your practice problems, tick off all 6 Unit 03 checkboxes on your master progress page.

Test yourself at the unit checkpoint

Before moving to Unit 04, you need to prove to yourself that your calculation skills are solid. Solve each of the following problems without looking at your notes first.

Try to estimate the answer mentally before reaching for a calculator. Write the problem in your notebook, then show full working.

Checkpoint problems:

How many moles of water are produced when 4g of H2 reacts with excess O2?
What mass of NaOH is needed to prepare 250 cm3 of 0.1 mol/dm3 solution?
If 5.6g of an oxide of iron contains 4.2g of iron, find the empirical formula.

Record your answers and full working in your notebook under the heading "Unit 03 Checkpoint".
Check your answers against the methods shown in the videos or your resource book.
If you cannot solve all three confidently, go back and re-watch the relevant video sections before continuing.

This unit is the gateway to everything that follows

Unit 03 feeds directly into Unit 04 (gas law calculations), Unit 05 (enthalpy calculations), Unit 11 (rate law calculations), and Unit 12 (equilibrium constant calculations). If your calculation skills are weak here, every one of those units will be harder than it needs to be.

Spend extra time on this unit if needed. It is better to take an extra week here than to struggle through four future units.

Your calculation toolkit is now ready. Next up, you will put these skills to work with gas law problems in Unit 04, where every equation depends on the mole and unit conversion fluency you just built.

Unit 04 - Gaseous State of Matter

You have built a solid calculation toolkit in Unit 03. Every mole conversion and stoichiometry formula you practiced is about to pay off.

Unit 04 covers the gaseous state of matter, where you will use mathematical relationships to predict how gases behave under changing conditions. The biggest trap in this unit is not the concepts themselves. It is getting the unit conversions wrong.

In this step, get ready to:

Watch all 5 Unit 04 videos on the gaseous state of matter (~17.5 hours).
Complete active study tasks including particle diagrams, gas law problems, and graphing exercises.
Pass the unit checkpoint to confirm your understanding before moving on.

Write your learning objectives and watch-points

Before pressing play on Video 1, open a fresh section in your notebook for Unit 04. Writing your objectives first gives your brain a filter for what to pay attention to during each lecture.

Write the heading Unit 04 - Gaseous State of Matter at the top of a new page in your notebook.
Copy the following learning objectives below the heading. By the end of this unit, you should be able to:

Describe particle arrangement and movement in solids, liquids, and gases.
Explain the ideal gas concept and its assumptions.
Apply PV = nRT to solve gas problems.
State and apply Boyle's Law, Charles' Law, and Avogadro's Law.
Explain deviations from ideal gas behavior.
Perform calculations involving gas mixtures using Dalton's law of partial pressures.

Below your objectives, write a Watch-Points section with these three reminders:

ALWAYS convert temperature to Kelvin and volume to the correct unit BEFORE applying any gas equation.
The gas constant R = 8.314 J mol-1 K-1. When using this value, pressure must be in Pa and volume in m3.
Unit conversion errors are the number one reason students lose marks in this unit.

Why study gas laws if they are only worth 4.25 marks?

Unit 04 is the lightest unit by mark allocation at approximately 4.25 marks out of 150.

However, the gas law calculations you learn here feed directly into Unit 12 (Chemical Equilibrium), which is worth approximately 18 marks. When you calculate Kp values in Unit 12, you will rely on the PV = nRT relationship and unit conversions you master here.

Complete your active study tasks

Watching passively will not build the problem-solving speed you need for the exam. After every 2-3 videos, pause and complete these tasks in your notebook.

After Videos 1-2, complete these tasks:

Draw and label particle arrangement diagrams for a solid, a liquid, and a gas. Show the spacing, arrangement, and movement of particles in each state.
Write down all the properties of an ideal gas from the lecture. These assumptions define when PV = nRT applies perfectly.

After Videos 3-5, complete these tasks:

Solve at least 15 gas law problems from your resource book. Focus on problems that require PV = nRT, Boyle's Law, Charles' Law, and Dalton's law of partial pressures.
Practice converting units for every problem: atm to Pa, cm3 to dm3 to m3, and Celsius to Kelvin. Write the conversion step explicitly each time.
Draw and label three graphs in your notebook: P vs V (at constant T), P vs T (at constant V), and V vs T (at constant P). Annotate each graph with the law it represents.

Write the conversion step every single time

Even if you can do a conversion in your head, write it out. In the exam, missing conversion steps means lost marks even if your final answer is correct.

Tick off each video's checkbox on your master progress page as you complete it.

Pass the unit checkpoint

Before moving to Unit 05, close your notebook and try to answer all three questions below from memory. This is how you confirm whether the concepts have truly stuck.

Answer these three checkpoint questions without looking at your notes:

A gas occupies 5 dm3 at 2 atm. If pressure increases to 4 atm at constant temperature, what is the new volume?
Calculate the pressure exerted by 1.5 mol of gas in a 8.314 dm3 container at 70 degrees Celsius.
Explain why real gases deviate from ideal behavior at high pressure and low temperature.

What if I cannot answer all three?

If any question trips you up, go back to the specific video that covered that topic. Re-watch the relevant section and rework the related problems in your resource book before moving on.

Write your checkpoint answers in your notebook.
Tick off all 5 Unit 04 checkboxes on your master progress page.

Your gas law foundation is solid. Next up, you will tackle Unit 05 (Energetics), where enthalpy calculations and Hess's Law bring a whole new set of energy puzzles to solve.

Unit 05 - Energetics

You have conquered gas laws and the ideal gas equation in Unit 04. Your calculation skills are getting sharper with every unit.

Unit 05 shifts focus from physical properties of gases to the energy changes that happen during chemical reactions. This unit is worth approximately 10 marks and introduces concepts like Hess's Law and Born-Haber cycles that connect directly to equilibrium calculations in Unit 12.

In this step, get ready to:

Write learning objectives and key watch-points for all 6 energetics videos.
Complete active study tasks including Hess's Law calculations and Born-Haber cycles.
Pass the unit checkpoint to confirm your understanding before moving on.

Write your learning objectives and watch-points

Energy changes drive every chemical reaction. Understanding exactly how much energy is released or absorbed tells you whether a reaction will happen spontaneously and how stable the products are.

Open your notebook to a fresh page and write Unit 05 - Energetics at the top.
Write down each of the following learning objectives. By the end of this unit you should be able to:

Define enthalpy, enthalpy change, and standard conditions.
Calculate enthalpy changes using Hess's Law.
Define and calculate: enthalpy of formation, combustion, neutralization, atomization, bond dissociation, lattice energy, hydration energy, and solution energy.
Draw and interpret Born-Haber cycles.
Interpret energy profile diagrams.

What should I watch out for in this unit?

Hess's Law calculations are guaranteed in the exam. Practice drawing energy cycles until you can do them without hesitation.

Sign conventions are critical. Exothermic reactions have a negative delta H. Endothermic reactions have a positive delta H. Mixing these up will cost you marks on every calculation in this unit.

Write the sign convention rule at the top of your Unit 05 page as a permanent reference: Exothermic = negative delta H, Endothermic = positive delta H.
Open the Unit 05 - Energetics playlist on YouTube and start Video 1.
As you watch, note down any new terms and their definitions. Pay special attention to how Pasindu sir draws energy cycles step by step.

Complete active study tasks after every 2-3 videos

Energetics has two halves. The first half covers enthalpy definitions and Hess's Law. The second half introduces lattice energy, Born-Haber cycles, and solution energy.

After videos 1-3

Create a definitions page listing every type of enthalpy change covered so far. For each one, write its full definition and whether the sign is positive or negative.
Include at minimum: enthalpy of formation, enthalpy of combustion, enthalpy of neutralization, enthalpy of atomization, and bond dissociation energy.
Solve 5 Hess's Law calculation problems from your resource book. Show all working and include units at every step.

Show your steps for marks

Remember what Pasindu sir emphasizes for calculation-heavy units. Even if you know the final answer, missing intermediate steps means lost marks. Write out every step of your Hess's Law cycles clearly.

After videos 4-6

Draw a complete Born-Haber cycle for NaCl. Label every energy step: atomization of Na, ionization of Na, atomization of Cl, electron affinity of Cl, and lattice energy.
Draw a second Born-Haber cycle for MgO. Note how the double charges on Mg2+ and O2- change the magnitude of ionization and electron affinity steps.
Solve problems involving lattice energy, hydration energy, and solution energy from your resource book.
Compare your Born-Haber cycle diagrams and problem solutions to the worked examples in the resource book. Fix any mistakes or missing labels.
Add lattice energy, hydration energy, and solution energy to your definitions page with their signs.

Why do Born-Haber cycles matter?

Born-Haber cycles let you calculate lattice energy indirectly, since you cannot measure it in a lab. The cycle breaks ionic compound formation into measurable steps and uses Hess's Law to find the missing value.

Getting comfortable with these diagrams now saves you time in the exam. They appear regularly in structured essay questions worth 8-10 marks each.

Tick off each video on your master progress page as you complete it. All 6 checkboxes for Unit 05 should be filled before continuing.

Test yourself at the unit checkpoint

Close your notebook and attempt each problem below from memory. Only check your notes after you have written a complete answer.

Problem 1: Using Hess's Law, calculate the enthalpy of formation of methane given combustion data for carbon, hydrogen, and methane. Write out each step of your cycle.
Problem 2: Draw a complete Born-Haber cycle for the formation of CaCl2. Label every energy step including both ionization energies of calcium and both electron affinities of chlorine.
Problem 3: Explain why lattice energy increases with ionic charge and decreases with increasing ionic radius. Use specific examples to support your explanation.

How do I know if I passed the checkpoint?

You should be able to answer all three problems confidently without looking at your notes. If you struggled with the Hess's Law calculation, re-watch the relevant section and solve 3 more practice problems before moving on.

If the Born-Haber cycle for CaCl2 tripped you up, compare it side by side with your NaCl cycle. CaCl2 adds a second ionization energy for calcium and doubles the chlorine steps. Trace through each difference carefully.

Finding Hess's Law cycles confusing?

The most common mistake is getting the direction of arrows wrong in the cycle. Always start from elements in their standard states at the top. Formation goes down. If a path goes up, the sign flips.

Help me understand how to set up a Hess's Law energy cycle with the correct arrow directions.

Record your checkpoint answers in your notebook below your Unit 05 notes.
Confirm all 6 Unit 05 checkboxes are ticked on your master progress page.

How does Unit 05 connect to what comes next?

The enthalpy concepts you just learned feed directly into Unit 12 (Chemical Equilibrium). When you study how temperature affects equilibrium position, you will use the sign of delta H to predict which direction the equilibrium shifts. A solid grasp of exothermic vs endothermic here makes Unit 12 significantly easier.

Your energetics foundation is locked in. Next up is Unit 06, the biggest and highest-scoring unit on the entire paper at approximately 22 marks.

Unit 06 - S, P and D Block Elements

Your energetics foundation is solid. You can calculate enthalpy changes, draw Born-Haber cycles, and apply Hess's Law with confidence.

Unit 06 is the biggest and highest-scoring unit on the A/L Chemistry paper. It carries approximately 22 marks, which is close to one quarter of the entire exam.

In this step, get ready to:

Write learning objectives and watch-points for all 8 videos covering s, p, and d block elements.
Build flashcards and reaction maps through active study tasks after every 2-3 videos.
Pass the unit checkpoint by answering self-test questions from memory.

Write your learning objectives and watch-points

This unit covers three major element groups across the periodic table. Before starting each video, write these objectives in your notebook.

By the end of this unit, you should be able to:

Describe Group 1 and Group 2 element reactions with water, oxygen, and acids.
Explain thermal stability trends of nitrates, carbonates, and hydroxides down each group.
Describe properties and reactions of Group 17 elements (halogens).
Explain d-block element properties including variable oxidation states, colored compounds, and catalytic behavior.
Identify ions through qualitative analysis using flame tests, precipitation reactions, and gas tests.
Write balanced equations for all key reactions covered in the unit.

This unit has all-or-nothing marking

Unlike calculation units where showing your working earns partial marks, Unit 06 questions are identification-based.

If you know the answer, you get full marks. If you do not, you get zero. This makes memorization and active recall essential.

What should I focus on while watching?

Pay close attention to how each group's reactions differ as you move down the periodic table. Trends are a common source of MCQ questions.

For qualitative analysis, note the exact colors of precipitates and flame tests. These details are tested directly and frequently.

Complete active study tasks after every 2-3 videos

Inorganic chemistry rewards active recall more than any other unit. Watching passively will not build the knowledge you need for this section of the exam.

After every 2 videos, complete these tasks:

Write out all reactions covered in that session from memory. Check against your notes and correct any mistakes.
Continue building your flashcards for flame test colors, precipitate colors, and gas tests.
Build a "reaction map" for each group showing what happens when elements react with water, oxygen, and acids.

Color-code your flashcards

Use different colors on your flashcards. Red for things you keep forgetting, blue for formulas and equations, green for definitions. This visual separation speeds up revision and recall during the exam.

After all 8 videos, complete this final task:

Do a complete practice run of qualitative analysis. Given a set of observations, identify the ions present.

Why a full qualitative analysis practice run?

The exam does not test individual flame tests or precipitate reactions in isolation. It combines multiple observations and asks you to identify the unknown compound.

Practising the full analysis workflow trains you to connect observations into a logical chain. This is the skill that earns marks.

Test yourself at the unit checkpoint

Before moving to Unit 11, answer these questions without looking at your notes.

Write the reaction of potassium with water. What would you observe?
How do you distinguish between Na+ and K+ ions in a mixture?
Explain why lithium behaves differently from other Group 1 elements.
What color is the flame test for calcium?
What precipitate forms when NaOH is added to a solution containing Fe3+ ions?

If you cannot answer all five confidently, re-watch the relevant sections before moving on.

Why this checkpoint matters more than others

Unit 06 tests factual recall directly. In calculation units, you can work through a problem step by step even when unsure. Here, you either know the answer or you do not.

Spending extra time on this unit has the highest return on marks in the entire syllabus. 22 marks from a single unit is a significant chunk of your total grade.

Once you pass the checkpoint, tick off all 8 Unit 06 checkboxes on your master progress page.

You have conquered the biggest unit on the paper. Next up is Unit 11, where you will explore how fast reactions happen and what factors control their speed.

Unit 11 - Chemical Kinetics

You have conquered Unit 06, the biggest and most demanding unit in the syllabus. Your tracker now shows six completed units with all their checkboxes ticked.

Chemical kinetics studies how fast reactions happen and what controls their speed. The rate law concepts from this unit feed directly into Unit 12 on chemical equilibrium, so mastering them here will make equilibrium calculations click.

In this step, get ready to:

Write Unit 11 learning objectives and key watch-points in your notebook.
Complete active study tasks after every 2-3 videos.
Pass the Unit 11 checkpoint before moving on to equilibrium.

Write your learning objectives and watch-points

Before starting each video, open your notebook to a fresh Unit 11 section and write down these objectives. By the end of this unit, you should be able to:

Define rate of reaction and explain how it is measured.
Explain the factors affecting reaction rate: concentration, temperature, surface area, and catalyst.
Explain collision theory and activation energy.
Interpret rate-concentration graphs and determine rate laws from experimental data.
Understand the concept of reaction order.
Draw and interpret energy profile diagrams with and without catalysts.

Key watch-points for this unit

Rate law expressions and how to determine reaction order from experimental data are common structured essay questions. Practice reading data tables and writing rate equations until it feels automatic.

The rate constant (k) and the equilibrium constant (Kc) are completely different quantities. k describes how fast a reaction proceeds. Kc describes the ratio of products to reactants at equilibrium. Do not mix them up.

Complete active study tasks after every 2-3 videos

Watching without doing leads to a false sense of understanding. Pause after every 2-3 videos and complete the matching tasks below.

After Videos 1-3:

Write a clear definition of rate of reaction in terms of change in concentration over time.
Draw energy profile diagrams for an exothermic reaction and an endothermic reaction.
Draw the same two diagrams again, this time adding the curve for a catalysed reaction. Label the activation energy, enthalpy change, and the lowered activation energy with the catalyst.

After Videos 4-6:

Practice determining rate laws from experimental data by solving at least 5 problems from your resource book.
Solve problems involving the Arrhenius equation if it was covered in the videos.
Make a summary table of all factors affecting rate (concentration, temperature, surface area, catalyst). For each factor, explain the effect using collision theory.

Show your working in full

In the A/L exam, calculation-based units require you to show every step of your working. Even if you know the final answer, missing steps mean lost marks. Write units on every quantity.

Test yourself at the unit checkpoint

Before moving on to Unit 12, close your notebook and answer all three questions from memory. Only check your notes after you have written your best attempt.

If doubling the concentration of A doubles the rate, what is the order with respect to A?
Draw an energy profile diagram for a catalysed exothermic reaction. Label the activation energy, enthalpy change, and the effect of the catalyst.
Explain why increasing temperature increases reaction rate using both collision theory and the Maxwell-Boltzmann distribution.

What if I cannot answer all three confidently?

Re-watch the relevant video sections before continuing. Kinetics is the direct foundation for equilibrium. Gaps here will cost you marks in Unit 12, which is worth roughly 18 marks on the exam.

Record your checkpoint answers in your notebook.
Tick off all 6 Unit 11 checkboxes on your master progress page.

Your kinetics foundation is solid. Next up is Unit 12 on chemical equilibrium, the second-highest scoring unit on the entire paper at roughly 18 marks.

Unit 12 - Chemical Equilibrium

You now understand how fast reactions happen. Unit 11 gave you the tools to measure reaction rates, determine rate laws, and explain why temperature and catalysts speed things up.

Unit 12 asks a different question: how far does a reaction go? This is the second highest-scoring unit on your exam at approximately 18 marks.

In this step, get ready to:

Write learning objectives and key watch-points for all 7 equilibrium videos.
Complete active study tasks including Kc/Kp calculations and Le Chatelier's principle predictions.
Pass the unit checkpoint to confirm your understanding before moving on.

Write your learning objectives and watch-points

Before starting each video, write these objectives in your notebook. By the end of this unit you should be able to:

Explain dynamic equilibrium and its characteristics.
Write Kc and Kp expressions for any balanced equation.
Calculate Kc and Kp from equilibrium concentrations and pressures.
Convert between Kc and Kp using the relationship Kp = Kc(RT)^delta n.
Apply Le Chatelier's principle to predict shifts in equilibrium.
Explain the effect of concentration, pressure, temperature, and catalysts on equilibrium position.
Interpret equilibrium using Kc values. Kc greater than 10^3 means products dominate. Kc less than 10^-3 means reactants dominate.

Why is this unit so important?

Unit 12 carries approximately 18 marks. That is roughly one-fifth of your entire exam paper, making it the second highest-scoring unit after Unit 06.

It builds directly on your Unit 03 (calculations), Unit 04 (gas laws), and Unit 11 (kinetics) knowledge. If those foundations are solid, you are well prepared for this final unit.

Write these key watch-points alongside your objectives:

This unit combines calculation and conceptual understanding. You need both to score well.
Always write "assume the gas behaves ideally" before applying gas equilibrium equations in your written answers.
Le Chatelier's principle questions appear in every exam paper. Treat this topic as guaranteed marks.
Kc is temperature-dependent only. Changes in concentration shift the equilibrium position but do not change the value of Kc.

Kc only changes with temperature

Many students lose marks by claiming that adding more reactant increases Kc. It does not. Adding reactant shifts the equilibrium position toward products, but Kc stays the same.

Only a temperature change alters the value of Kc. Make sure you are crystal clear on this distinction before the exam.

Complete active study tasks after each video set

Equilibrium demands hands-on practice. Watching the videos without solving problems will not build the skills you need for the exam.

After watching Videos 1 through 3, complete these tasks in your notebook:

Write Kc expressions for 10 different reactions.
Note why pure solids and liquids are not included in equilibrium expressions.
Practice the ICE table method (Initial, Change, Equilibrium) for at least 3 problems.

What is the ICE table method?

ICE stands for Initial, Change, Equilibrium. It is a systematic way to organize your equilibrium calculations.

Set up a table with a column for each species in the reaction. Fill in the initial concentrations, express the changes using a variable (usually x), then solve for the equilibrium values. This method prevents sign errors and keeps complex problems manageable.

After watching Videos 4 through 7, complete these tasks:

Solve at least 10 Kc/Kp calculation problems from your resource book.
Practice Le Chatelier's principle predictions for changes in concentration, pressure, temperature, and adding a catalyst.
Convert between Kc and Kp for at least 5 reactions using Kp = Kc(RT)^delta n.

Test yourself with the unit checkpoint

Before marking this unit as complete, answer these questions without looking at your notes.

Write the Kc expression for N2 + 3H2 = 2NH3.
If Kc = 4.0 x 10^8 at 500K, what does this tell you about the position of equilibrium?
For the reaction 2SO2 + O2 = 2SO3 (exothermic), predict the effect of increasing temperature, increasing pressure, and adding a catalyst.
Calculate Kp if Kc = 0.5 for a reaction where delta n = -2 at 300K.

How to interpret Kc values

If Kc is greater than 10^3, the products dominate. The reaction has gone nearly to completion.

If Kc is less than 10^-3, the reactants dominate. The reaction has hardly proceeded.

Values in between mean you have a true equilibrium with significant amounts of both reactants and products present.

If you cannot answer all four questions confidently, re-watch the relevant sections before moving on.

Record your checkpoint answers in your notebook.
Tick off all 7 Unit 12 checkboxes on your master progress page.

All 51 checkboxes on your master progress page are now ticked. You have completed the entire video lecture series across all 8 units.

Your theory foundation is complete. Next up, you will condense each unit into a one-page cheat sheet that becomes your ultimate exam revision tool.

Secret mission

Build Your Exam-Ready Cheat Sheets

You have worked through 51 videos and 8 unit checkpoints. Now condense everything you have learned into powerful one-page summary sheets that become your ultimate revision weapon for the A/L Chemistry exam.

Before you go

Clean Up Your Resources

Decide whether to keep your study system active, pause it for a break, or archive it now that you have completed the 8 units. This project runs entirely on free YouTube content and a physical notebook, so there are no ongoing costs.

Resources you used:

YouTube playlists from Pasindu Balasooriya's channel (51 videos across 8 units).
Your chemistry tracking notebook (master progress page, unit notes, checkpoint answers).
NIE Resource Book (your existing reference material).
Flashcards for Unit 06 (flame tests, precipitate colors, gas tests).
Exam-ready cheat sheets (if you completed the Secret Mission).

Keep everything running

No action needed. Choose this if you are still actively studying or plan to start past paper practice soon.

Keep your notebook in your regular study area so it stays part of your daily routine.
Bookmark the YouTube playlists in your browser for quick access during revision.
Keep your flashcards and cheat sheets nearby for regular self-testing.

Pause - I'll come back to this later

Organize your materials so you can pick up exactly where you left off when you return.

On your master progress page, write today's date and the last unit/video you completed.
Place a sticky note or bookmark at the page where you stopped in your notebook.
Save all YouTube playlist links in a single browser bookmark folder named "AL Chemistry Study".
Store your notebook, flashcards, and cheat sheets together in one place so nothing gets lost.

Delete - I don't want to use this again

Remove your study tracking materials if you have finished the exam or no longer need them.

Remove the YouTube playlist bookmarks from your browser.
Recycle flashcards you no longer need.
Consider keeping your notebook and cheat sheets as a reference. Chemistry knowledge stays useful well beyond the exam.

Mission accomplished

That's a Wrap!

Nice work. You have systematically worked through 51 lectures covering 8 major units of A/L Chemistry with active engagement at every step.

You've learned how to:

Completed 178+ hours of structured chemistry study with a progress tracker, self-check assessments, and active note-taking across all 8 units.
Identified the exam weight distribution for strategic revision, knowing that Unit 06 (S, P, D Block) carries ~22 marks and Unit 12 (Chemical Equilibrium) carries ~18 marks.
Connected concepts across units, understanding how chemical calculations feed into gas laws, equilibrium, and energetics.
Created 8 exam-ready cheat sheets that condense each unit into a one-page rapid revision tool.

Ready to quiz yourself?