The 3 Golden Formulas You MUST Memorize (From Our Notes PDF)

Every mole calculation in your exam uses one of these three formulas. Master these, and you've mastered 80% of stoichiometry.

Formula 1: The Mole Equation (The Foundation)

Number of moles = Mass (g) ÷ Molar Mass (g/mol)

Exam Application: Use this when you're given mass and need to find moles, or vice versa. Write this formula at the top of every stoichiometry question.

Formula 2: The Concentration Triangle (For Solutions)

Concentration (mol/dm³) = Moles ÷ Volume (dm³)

Exam Trick: Volume must be in dm³! If given cm³, divide by 1000. This simple conversion mistake costs students 3-4 marks per paper.

Formula 3: The Gas Volume Equation (Students' Worst Nightmare)

Volume of Gas (dm³) = Moles × 24 dm³ (at r.t.p.)

Critical Warning: This only works at room temperature and pressure (r.t.p.). If the question says "different conditions," you must use PV=nRT (for A-Level). Our course has a 10-minute drill to eliminate this confusion forever.

The Mole Roadmap (From Our Cheat Sheet)

Follow this flowchart for ANY stoichiometry problem:

Step 1: Write the balanced chemical equation (ALWAYS!)
Step 2: Convert given quantity (mass/volume/concentration) to moles using Formulas 1-3
Step 3: Use the mole ratio from the balanced equation to find moles of required substance
Step 4: Convert back to the required unit (mass/volume/concentration)

This 4-step roadmap appears in 90% of stoichiometry questions across O Level 5070 and IGCSE 0620 past papers. Our course breaks down each step with 15 worked examples.

Common Conversion Factors (Save This Table!)

What You're Given Conversion to Moles Common Exam Trap
Mass (grams) Divide by molar mass (Ar or Mr) Using atomic number instead of atomic mass
Volume of Solution (cm³) Convert cm³ to dm³ (÷1000), then use concentration Forgetting to convert cm³ to dm³
Volume of Gas at r.t.p. Divide by 24 dm³ Using 22.4 dm³ (that's for 0°C, not room temp!)
Number of Particles Divide by 6.02 × 10²³ (Avogadro's constant) Confusing particles with moles

Exam Super-Tip: The "Mole Ratio" Shortcut

In the balanced equation 2Mg + O₂ → 2MgO, the mole ratio is 2:1:2. This means 2 moles of Mg produce 2 moles of MgO. So the moles of MgO = moles of Mg (direct 1:1 ratio here). Spotting these ratios instantly saves 5 minutes per question!

This free crash course covers 10% of stoichiometry. For 100% mastery, you need our complete system.

Prof. Faisal Janjowa - 25+ Years Examiner

From The Examiner Who Writes The Questions

"With 25+ years of setting and marking papers, I can tell you that stoichiometry is the most predictable topic in O Level and IGCSE Chemistry. The same 5-6 question types appear every year. In my 35-minute crash course, I don't just teach formulas—I teach you to recognize question patterns instantly. For example, if a question gives you mass and asks for gas volume, it's always: mass → moles → gas volume. That's the level of pattern recognition that gets you A*."

Why Our 35-Minute Course Beats 20 Hours of YouTube

The Scattered Approach

  • Watch random YouTube videos (often outdated)
  • Download 5 different mole concept notes pdf files
  • Practice without understanding patterns
  • Time: 15-20 hours, minimal improvement
  • Cost: Free but ineffective

Our Systematic Method

  • 35-minute focused video following exam patterns
  • One comprehensive notes PDF with cheat sheets
  • Practice with 20 pattern-based questions
  • Time: 35 minutes to core mastery
  • Cost: $35 (less than a textbook)

"I used to panic at every stoichiometry question. The 3-formula system and roadmap from this course changed everything. I went from guessing answers to solving them in under 2 minutes. Worth every penny of the $35!"

– Sarah L., Singapore
O Level 5070 Student (A* Achieved)

"As a teacher, I recommend this to all my struggling students. The way it simplifies mole conversions with the flowchart is genius. My students' average score on stoichiometry questions improved by 40% after taking this course."

– Mr. Wong, Chemistry Teacher
International School, Hong Kong

What You Get In The $35 Course

35-Minute HD Video - Watch anytime, anywhere
Complete Notes PDF - 25 pages with diagrams
20 Solved Problems - Covering all question types
Stoichiometry Cheat Sheet - 1-page quick reference
Q&A Support - Get your doubts cleared
Lifetime Access - For all future revisions
GET INSTANT ACCESS FOR $35

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