You are sitting in the exam hall, your pen is hovering over the paper, and you are staring at a question asking for the reaction between Sodium Hydroxide and Sulfuric Acid. You studied this. You know you did. But suddenly, your brain goes blank. Is it NaSO4? Or Na2SO4?
It is frustrating. It feels like your village people are at work.
But here is the truth: Chemistry isn’t magic, and it isn’t just for “gurus.” The problem isn’t your brain; it’s your method. Most students try to cram formulas the same way they cram definitions for Government or CRK. That doesn’t work for Science.
If you are looking for how to remember chemical formulas and equations easily, you need a system, not just a photogenic memory.
I’ve tutored hundreds of students for WAEC and JAMB, and I’ve seen what works. It’s not about “la cram, la pour.” It’s about understanding the code. Here is how you can hack the system.
1. Stop Cramming, Start with Valency
This is where 80% of students mess up. They try to memorize that water is H2O and Carbon Dioxide is CO2 as separate facts. That’s a waste of brain space.
You need to learn the Valency of the first 20 elements and common radicals (like Sulfate, Nitrate, Carbonate). Think of valency as the number of hands an element has to hold onto another element.
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Sodium (Na) has a valency of +1 (One hand).
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Oxygen (O) has a valency of -2 (Two hands).
To combine them, they swap numbers. Sodium gives its “1” to Oxygen, and Oxygen gives its “2” to Sodium. Result? Na2O.
Once you master this exchange, you don’t need to memorize thousands of formulas; you can just build them on the spot. It’s a foundational skill, much like the discipline required in developing 10 effective study habits every student should develop. If you skip the basics, you struggle.
2. Use Mnemonics (The Naija Style)
Let’s be honest, dry textbooks are boring. Our brains remember funny, weird, or rhythmic things much better.
For the Reactivity Series (which tells you which metal will displace another in an equation), don’t just stare at the list. Use a sentence.
I teach my students this one:
“Popular Scientists Can Make A Zoo In The Low Humid Country More Satisfactory.”
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Popular – Potassium (K)
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Scientists – Sodium (Na)
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Can – Calcium (Ca)
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Make – Magnesium (Mg)
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A – Aluminium (Al)
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Zoo – Zinc (Zn)
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In – Iron (Fe)
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The – Tin (Sn)
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Low – Lead (Pb)
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Humid – Hydrogen (H)
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Country – Copper (Cu)
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More – Mercury (Hg)
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Satisfactory – Silver (Ag)
Create your own. Use slang. Use names of your friends. If it makes you laugh, it sticks. This is a creative way to learn, similar to how we use proverbs in debate greetings and proverbs to catch the audience’s attention.
3. The “Table Tennis” Method for Balancing Equations
Balancing equations scares people. It looks like advanced calculus. But it’s actually just a game of keeping scores equal.
Don’t try to do it all in your head. That’s a recipe for a headache.
Try this steps:
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Draw a line down the middle of the equation (under the arrow).
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List the atoms on the Left (Reactants) and the Right (Products).
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Count them. Left: 2 Hydrogen. Right: 2 Hydrogen. Good.
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If they don’t match, change the big number in front (the coefficient). Never change the small number (the subscript).
Treat it like a game of table tennis. Ping pong back and forth until the numbers are equal. For a visual guide on this, resources like Khan Academy’s Balancing Equations guide can be incredibly helpful.
4. Active Recall: Stop Reading, Start Writing
I see this mistake all the time. A student sits with a notebook, reading the same page over and over for three hours. They feel productive.
But they aren’t learning. They are just recognizing the words.
To really know how to remember chemical formulas and equations easily, you must test yourself.
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Look at a formula.
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Cover it.
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Write it down from memory.
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Check it.
If you got it wrong, write it five times. This forces your brain to create a pathway for that information. It’s hard work, but it’s fast work. If you are short on time before WAEC, this is exactly how to prepare for an exam in a short time.
Common Mistakes That Cost You Marks
Even if you memorize the formula, you can still lose marks if you aren’t careful. Here is what to watch out for:
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Case Sensitivity: CO is Carbon Monoxide. Co is Cobalt. If you write your letters carelessly, you change the chemical meaning entirely.
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State Symbols: Don’t ignore the (s), (l), (g), and (aq). In WAEC marking schemes, writing H2O(g) instead of H2O(l) can sometimes cost you the full mark.
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Subscripts vs Coefficients: Writing 2O is totally different from O2. One is two separate atoms; the other is a molecule.
Conclusion
Chemistry doesn’t have to be the subject that ruins your WAEC result.
It’s not about being a genius; it’s about consistency. Start with the valencies today. Make up a funny song for the periodic table tonight. Before you know it, writing $H_2SO_4 + 2NaOH \rightarrow Na_2SO_4 + 2H_2O$ will feel as natural as writing your own name.
You’ve got this.
For more in-depth science resources, checking out the syllabus on the West African Examinations Council (WAEC) official website keeps you aligned with what examiners actually want.
What’s the hardest formula you’ve tried to memorize? Let me know in the comments
