Vertex Tutoring GCSE & A-Level

23/07/2026

A-Level Chemistry Practical 2: Rates of Reaction | The Disappearing-Cross Experiment How does concentration affect the rate of a chemical reaction?

In this A-Level Chemistry practical lesson, we investigate the reaction between sodium thiosulfate and hydrochloric acid using the disappearing-cross method.

You’ll learn:

🧪 How to carry out the practical safely⏱️ How to calculate relative rate using 1 ÷ time📈 How to plot and interpret the results💥 How concentration affects collision frequency✅ How to identify anomalies and improve the investigation📝 How to answer related examination questions accurately

This lesson is particularly useful for OCR B A-Level Chemistry students, as well as anyone revising rates of reaction and collision theory.

Watch the complete lesson and try the calculation question included in the video.

If you need personalised support with A-Level or GCSE Chemistry, send us a message to discuss tutoring.

13/06/2026

A-Level Chemistry students often find practical questions difficult — not because the practical itself is impossible, but because exam questions usually test understanding, accuracy, evaluation, and calculations all at once.

In this video, I explain OCR B Chemistry Practical 1, focusing on enthalpy change and calorimetry.

This is especially useful if you are revising:
✅ how calorimetry experiments work
✅ why temperature change is measured
✅ how to use q = mcΔT
✅ common sources of error
✅ how to approach practical-based exam questions

Practical skills are a key part of A-Level Chemistry, and understanding the reasoning behind each step can make a big difference in exam answers.

I offer GCSE and A-Level Science tutoring, including support with Chemistry content, calculations, practical skills, and exam technique.

Feel free to message me if you would like extra support.

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In this video, I explain OCR B A-Level Chemistry Practical 1, focus...

27/05/2026

A lot of students leave revision sessions feeling productive simply because they spent several hours “doing revision,” when in reality very little information was actually retained long-term.

One of the biggest reasons this happens is that familiarity is often mistaken for understanding.

For example, after rereading notes multiple times, a topic can start to feel very easy because the brain recognises the information visually. However, recognition is very different from being able to recall and apply information independently in an exam setting.

A useful way to test whether revision is actually effective is to remove all notes completely and ask:
• Can I explain this topic out loud from memory?
• Can I answer unfamiliar exam questions on it?
• Can I link ideas together without prompts?
• Could I teach this concept to somebody else clearly?

If the answer is no, the revision probably needs to become more active.

One strategy that helps many students is separating revision into two stages:

Stage 1:
Learning and understanding content.

Stage 2:
Training exam performance.

A lot of students spend too much time in stage 1 and not enough time applying knowledge under pressure.

Another very effective habit is keeping a “mistake log.”

Instead of only marking questions right or wrong, students can track:
• topics repeatedly forgotten
• command words that cause problems
• careless mistakes
• weak scientific vocabulary
• timing issues
• and question types that feel difficult.

Over time, patterns usually begin to appear very clearly.

This makes revision much more focused and prevents students from repeatedly revising topics they already know well while avoiding weaker areas unconsciously.

One of the strongest forms of revision is often not the most enjoyable one.

The revision methods that improve grades most effectively usually involve:
retrieval, correction, struggle, and repetition — because they force the brain to actively rebuild information rather than simply recognise it.

26/05/2026

A mistake I see very often with GCSE Science revision is students spending hours rereading required practical sheets without actually testing whether they understand the experiment itself.

With practical questions, understanding is usually far more important than memorisation.

A useful way to revise practicals is to ask yourself questions throughout the process instead of simply reading through the method passively.

For example:
• Why is this piece of equipment used?
• Why must this variable be controlled?
• What would happen if this step was changed?
• What result would I expect and why?
• What type of error could affect the data?

Students who regularly ask themselves these kinds of questions often become much better at handling unfamiliar practical questions in exams because they understand the scientific reasoning behind the experiment rather than memorising isolated steps.

Another very effective revision strategy is comparing practicals across Biology, Chemistry, and Physics to identify recurring patterns.

Many practical questions repeatedly assess the same core skills:
✔ interpreting data
✔ identifying patterns
✔ evaluating reliability
✔ explaining scientific processes
✔ and applying knowledge to unfamiliar situations.

One thing that helps massively is practising practical questions under timed conditions.

A lot of students understand the experiment when revising calmly at home, but struggle to organise explanations clearly under exam pressure. Practising under realistic timing conditions helps build structure and confidence much more effectively.

Required practical questions are often some of the most application-heavy questions on GCSE Science papers, which means developing scientific reasoning is usually much more valuable than trying to memorise mark schemes line-by-line.

21/05/2026

Many students struggle with GCSE Chemistry 6-mark questions not because they do not know the content — but because they panic when trying to structure their explanations under exam pressure.

In Chemistry, examiners are usually looking for:
✔ logical sequencing
✔ clear scientific reasoning
✔ precise terminology
✔ and linked explanations.

One of the biggest mistakes students make is writing disconnected facts without explaining the process step-by-step.

Questions involving electrolysis, bonding, equilibrium, or required practicals often reward students who can explain scientific processes clearly rather than simply memorising isolated points from revision notes.

Breaking the question down first and identifying:
• the command word
• the key scientific ideas
• and the logical order of the answer

can make a huge difference in longer-mark questions.

Save this for revision 📚

20/05/2026

Many students lose marks on GCSE Biology 6-mark questions not because they do not know the content — but because their explanations are not structured clearly enough.

A lot of answers contain correct scientific ideas, but:
• points are disconnected
• key terminology is too vague
• explanations are not linked logically
• or the question is not fully answered.

One of the biggest improvements students can make is learning how to structure explanations step-by-step rather than simply writing down everything they know about a topic.

Small changes in wording, organisation, and scientific reasoning can make a very large difference in longer-answer Biology questions.

Clear explanations usually score far better than rushed paragraphs.

Save this for revision 📚

19/05/2026

A lot of students lose marks on GCSE Science calculations even when they understand the topic and know the formula.

The issue is often exam technique rather than lack of knowledge.

One very common mistake is rushing straight into the calculator without first thinking carefully about:
• which values are actually needed
• whether unit conversions are required
• and what the question is specifically asking for.

A useful habit is underlining:
• the values given
• the units
• and the quantity you need to calculate.

This helps avoid mistakes such as:
• using the wrong number
• missing powers of 10
• or forgetting to convert units.

Another important tip:
Write the formula down FIRST before substituting numbers in.

This slows the process down slightly, but it massively reduces careless mistakes and also helps secure method marks if the final answer is incorrect.

A lot of students also round too early during calculations. This can sometimes change the final answer significantly, especially in Physics questions involving multiple steps.

A much safer approach is:
• keep the full calculator value throughout
• then round only at the very end.

Another thing many students do not realise:
Examiners can often still award marks for:
✔ the correct formula
✔ correct substitutions
✔ correct method
✔ logical working

even if the final answer is wrong.

This is why showing every step clearly is so important.

Doing calculations entirely “in your head” may feel faster, but it often increases the risk of losing easy marks through:
• copying errors
• calculator input mistakes
• unit mistakes
• or rounding errors.

One of the best ways to improve at GCSE Science calculations is to slow down slightly and focus on accuracy and structure rather than speed.

Clear, organised working usually gains far more marks than rushing.

18/05/2026

One of the biggest reasons students lose marks on GCSE Science 6-mark questions is not a lack of knowledge — it is poor structure.

A very common mistake is writing everything they know about a topic as quickly as possible, hoping that the correct points are somewhere in the paragraph.

The problem is that examiners are usually looking for:
✔ logical progression
✔ linked scientific reasoning
✔ clear explanations
✔ relevant scientific vocabulary
✔ and answers that directly follow the question.

In many cases, a shorter but well-structured answer can score higher than a long paragraph with scattered points.

One thing that helps massively is slowing down for 20–30 seconds before writing and briefly planning the answer.

For example:
• What is the question ACTUALLY asking?
• Which scientific ideas do I need?
• In what order should I explain them?
• Have I answered every part of the question?

A useful structure for many 6-mark questions is:

Point → Explain → Link

Meaning:
• make a clear point
• explain the science behind it
• then connect it logically to the question.

Another important tip:
Use connectives such as:
“because”
“therefore”
“this means that”
“as a result”

These help explanations flow logically instead of sounding like disconnected facts.

Students also often lose marks by:
• repeating the question
• using vague wording
• missing scientific keywords
• or only answering one part of a multi-step question.

One of the best ways to improve at 6-markers is not simply “doing more revision,” but carefully analysing mark schemes and understanding HOW high-mark answers are structured.

Over time, students start recognising patterns in the way examiners expect explanations to be written.

Small exam technique improvements like these can make a very big difference across Biology, Chemistry, and Physics papers.

15/05/2026

One of the biggest GCSE Science mistakes students make is misunderstanding command words.

A student may know the science content well, but if the answer does not match what the question is asking for, marks can still be lost very easily.

Different command words require different styles of answers, and examiners are specifically looking for certain things.

For example:

• “Describe” questions usually require observations, trends, or stating what happens
• “Explain” questions require scientific reasoning and cause-and-effect links
• “Compare” questions need BOTH similarities and differences
• “Evaluate” questions require strengths, weaknesses, and a final judgement
• “Calculate” questions require full working, correct units, and careful rounding/significant figures

One of the biggest mistakes students make is writing everything they know about a topic instead of focusing directly on the command word.

A useful habit during exams is to pause before answering and ask yourself:

“What exactly is this question asking me to do?”

Small exam technique improvements can make a huge difference across Biology, Chemistry, and Physics papers.

14/05/2026

You may know the science… but these mistakes are still costing you marks.

A lot of GCSE students lose marks not because they don’t understand the content, but because of small exam technique mistakes that add up across the paper.

Some of the most common ones include:

❌ Ignoring command words
❌ Weak exam technique
❌ Missing marks on required practicals
❌ Passive revision habits
❌ Not analysing mistakes after past papers
❌ Poor structure in longer-answer questions

The good news is that these are all fixable.

Over the next few posts, I’ll break down each of these in more detail and explain practical ways to improve them before exam season.

Small improvements in exam technique can make a huge difference in GCSE Science.

Biology • Chemistry • Physics