Solved in Minutes: Mastering Le Chatelier’s Principle with Ms. Stephanie Todaro

At Crimson Global Academy (CGA), we’re proud to learn from some of the most passionate and experienced educators in the world. One of those teachers is Ms. Stephanie Todaro, our US Academic Dean and expert Chemistry Teacher, who recently broke down a famously tricky topic – Le Chatelier’s Principle – and showed students how to master it in just minutes.

With nearly two decades in education, Ms. Todaro has spent most of her career teaching Chemistry and AP Chemistry at top-tier independent schools. She holds a B.S. in Chemistry from Allegheny College and a Master’s in Science Education from the University of Pittsburgh. Since joining CGA in 2022, she’s led our science department with energy, clarity, and an unmatched dedication to student success.

Whether you’re preparing for AP exams or just trying to get a handle on how reactions work, Ms. Todaro’s insights can help you simplify even the most complex chemistry ideas, starting with this one.

What is Le Chatelier’s Principle?

Le Chatelier’s Principle is a fundamental rule in Chemistry that helps us understand how a system at equilibrium reacts when conditions change. Think of it as a chemical version of “cause and effect.” When you disturb a balanced reaction — by changing concentration, pressure, or temperature — the system will naturally shift in a way that tries to restore balance.

This principle is not only useful for tests and labs, but it’s also critical in real-world industries where optimising chemical yields is everything — like pharmaceuticals, energy production, and manufacturing.

Change in Concentration

Here’s the first trick: When you add more of something, the system will try to use it up.

• Add a reactant? The system shifts right, making more products.
• Remove a product? Same thing — the system shifts right to make more.

Example:
In a reaction involving PCl₅ ⇌ PCl₃ + Cl₂, if you add more PCl₅, the system shifts right to produce more PCl₃ and Cl₂. If you remove some Cl₂, it shifts right again to replace it.

Change in Pressure (for Gases)

Now think about pressure. This only matters if gases are involved.

• Increase pressure? The system shifts to the side with fewer gas molecules.
• Decrease pressure? It shifts to the side with more gas molecules.

Example:
If two moles of gas turn into one mole of product, increasing the pressure will shift the reaction towards the side with fewer moles (the product side), easing the pressure.

Change in Temperature

Here’s where heat becomes part of the equation.

• If the reaction is endothermic (absorbs heat), increasing temperature shifts it right.
• If it’s exothermic (releases heat), increasing temperature shifts it left.

Tip from Ms. Todaro: Always check whether heat is a “reactant” or a “product” in your reaction — that’s how you figure out which way the equilibrium will shift.

Why It Matters

Understanding Le Chatelier’s Principle can help you:

• Predict how a reaction will change under new conditions
• Improve your problem-solving speed in Chemistry exams
• Gain insights into real-life chemical processes like drug development or clean energy

With Ms. Todaro’s clear explanations, even the most abstract concepts become manageable. In just one session, students were already applying these ideas with more confidence and clarity — proof that the right teacher really can help you solve tough topics in minutes.

For all her expert tips on mastering Chemistry concepts like Le Chatelier’s Principle, watch the full video here. Don't miss this chance to learn from CGA’s Academic Dean herself!

Exam Prep Tips: How to Tackle Chemistry with Confidence

Preparing for high-stakes Chemistry exams — whether it's AP Chemistry, IGCSE Chemistry, or A Level Chemistry — can feel overwhelming, but with the right strategies, it becomes much more manageable. Here are the top tips to help students study smarter and perform at their best:

1. Understand the "why" – Instead of memorising chemical equations or definitions, focus on understanding why reactions happen. Le Chatelier’s Principle, for example, makes a lot more sense when you think of it as the system’s natural response to restore balance.
2. Practise visualisation – Chemistry is deeply visual. Use diagrams, equilibrium graphs, or even molecular models to help you “see” how changes in concentration, pressure, or temperature affect the reaction.
3. Solve past papers – One of the best ways to build exam confidence is to practise with past exam papers. This helps you get familiar with question styles, improve your time management, and refine your answering techniques.
4. Teach it to someone else – Teaching a concept to a friend or even saying it out loud to yourself is a powerful way to reinforce your understanding. If you can explain it clearly, you probably know it well.
5. Make use of digital tools – At CGA, students have access to Winston.ai, our AI assistant that provides instant lesson recaps, summaries, and helpful productivity tools. It’s perfect for reviewing key concepts just before a test or revisiting tricky topics quickly.

Explore Chemistry at CGA

At CGA, we offer a flexible and internationally recognised curriculum with options to suit every learner:

• IGCSE Chemistry – A strong foundational course introducing key principles and lab-based problem solving.
• A Level Chemistry – For students aiming for top universities in science and health-related fields.
• AP Chemistry – A rigorous, college-level course perfect for students pursuing university in the US or looking for advanced study.

Whether you’re exploring your interests or preparing for a specialised university pathway, CGA’s science curriculum is designed to challenge, support, and inspire.

Ready to Learn Smarter?

At CGA, we believe expert guidance makes all the difference. With passionate teachers like Ms. Todaro and a flexible, innovative curriculum, students don’t just learn — they thrive.

Join a school where tough topics get solved in minutes, and every question has an answer.