The Chemistry GCSE Required Practicals Showdown: Which are the hardest?

Welcome to the ultimate Chemistry Practical Showdown! In this contest of beakers and burners, we’re ranking the top three toughest secondary chemistry required practicals, as revealed by data from LbQ and insights from Al Heys, Head of Science at LbQ. Today, we’re focusing on Chemistry—but if you want to uncover the country’s toughest practicals across all sciences, and discover the nation’s most revised practical, make sure to sign up and download the free Cookbook—updated and revised for 2025!

Let’s dive in, starting with third place and working our way to the ultimate challenge!

In Third Place: Temperature Changes required practical

Sliding into the bronze spot is the Temperature Changes practical. On the surface, this experiment seems like a breeze—you mix an acid and an alkali, measure the peak temperature of the reaction, and observe the exothermic process unfold. Easy, right? Not quite!

Al Heys explains: “It’s not the actual practical that trips them up—it’s the building blocks leading up to it.” Students first need to grasp the essentials of neutralisation reactions and know the difference between exothermic and endothermic processes. Add to that the challenge of identifying variables, and it’s clear why many stumble before even setting up the apparatus.

What’s the remedy?

Al suggests more targeted practice on identifying variables and breaking down the foundational concepts before tackling the experiment itself. “Start with the basics,” he advises. “Make sure they’re confident with the theory, and the practical will fall into place.”

Practical Tip Alert!

One of the biggest time traps in practicals is overwriting methods. Kids often spend precious minutes painstakingly listing every step: "Collect the goggles, put the Bunsen burner in the gas tap, light…" when a quick, well-labeled diagram could do the job far more efficiently. 

We wanted to make doubly sure that students would still be awarded marks for this approach - so we went to AQA…

“Thank you for contacting AQA regarding extended response questions in our GCSE exam questions. Yes, students can use diagrams/sketches when answering these questions.”

They went on to point us in the direction of this helpful document, Teaching guide: exploring common misunderstandings, where on page 26, you can see an example of a student using a diagram in their answer. This approach not only saves time but also helps clarify their method without losing marks. Encourage them to grab those pencils and get sketching!

Related content:

Download your copy of the LbQ Cookbook

8 tips to teach your students how to revise for GCSE science

7 tips for teaching students how to revise for required practicals

In Second Place: Electrolysis required practical

Taking the silver medal is the notoriously tricky Electrolysis practical. It’s the bane of many students’ lives and with good reason. This isn’t just about splitting compounds—it’s about navigating a labyrinth of chemical terminology and concepts.

“Electrolysis is a classic ‘layer cake’ of complexity,” says Al. “Students need to understand ionic bonding and the formation of ions, electric circuits and electrolytes before they can even start thinking about electrodes and half-equations.” It’s a lot to digest, and for students who haven’t nailed these fundamentals, it’s like trying to bake a cake without flour—it just doesn’t work!

What’s the recipe for success?

Al recommends a spiral learning approach, revisiting electrolysis topics multiple times with increasing depth. “Start simple: get them familiar with the terminology, then layer on the practical applications,” he says. Pairing theory with hands-on practice can demystify even the trickiest electrochemical concepts.

And in First Place: Rates of Reaction required practical

Drumroll, please! The champion of challenging practicals is none other than Rates of Reaction. This experiment might seem straightforward—watching how fast a reaction occurs under different conditions—but it exposes a glaring gap in students’ understanding: variables.

“The root of the problem,” Al says, “is that students still don’t fully grasp the difference between independent, dependent, and control variables.” Without this foundational knowledge, they struggle to explain how changing one variable (like concentration) affects the reaction’s speed.

How do we flip the script?

Al emphasises the importance of drilling variable identification early and often. “If students can master variables, they’ll be much more confident approaching any practical, especially one as fundamental as this.” He also suggests integrating real-life analogies to make the concept more relatable: “Think of variables as ingredients in a recipe—changing one will alter the final dish!”

The Takeaway: master the basics, master the required practicals

While each of these practicals presents unique challenges, they all share a common thread: success depends on mastering the basics first. From understanding variables to breaking down complex concepts into manageable steps, the key is preparation.

And remember, as Al puts it, “A little extra time spent on the groundwork goes a long way. With the right approach, even the toughest practicals become manageable—and maybe even fun!”

Want to see how your students stack up against the rest of the country? Curious about the nation’s most revised practical? Download the free Cookbook—updated and revised for 2025—and unlock the full breakdown of tough-to-crack practicals across all sciences.