Introduction

Data-based questions in IB Chemistry trip up even strong students. They test not just your knowledge, but your ability to analyse unfamiliar data and apply concepts.

Here's how to handle them like a pro.

Read the Question First, Not the Data

Start by scanning the actual question. This helps you know what to look for in the graph or table.

Tip:

Read the question stem and look for key words like "compare," "explain," or "calculate." This tells you exactly what type of analysis the examiner wants.

Understanding what you're being asked prevents you from getting lost in irrelevant data details. Focus your analysis on what will answer the question.

Identify Trends

Look for patterns, not just individual values. Comment on increases, decreases, or anomalies.

What to look for in data:

Overall trends (increasing, decreasing, or constant)
Sudden changes or plateaus
Maximum and minimum values
Rates of change at different points
Unexpected values or anomalies

Don't just describe what you see — explain what the trend means. For example: "The rate increases initially then levels off, suggesting a limiting factor."

Link Back to Chemistry Concepts

Always tie your observations to theory. For example: "The increase in reaction rate can be explained by collision theory."

Connect rate changes to collision theory or catalysis
Link concentration changes to equilibrium principles
Relate temperature effects to kinetic molecular theory
Connect pH changes to acid-base theory

This is what separates high-scoring answers from basic descriptions. Examiners want to see that you understand the chemistry behind the data.

Practise With Past Paper Data Sets

These are the best preparation, but don't stop there — create your own practice questions from textbook graphs.

Effective practice strategies:

Work through data questions from multiple past papers
Time yourself to build exam speed
Practice explaining trends in different contexts
Create questions from graphs in your textbook

The more data sets you analyse, the faster you'll recognise common patterns and apply appropriate chemical explanations.

Structure Your Answers

Organize your response clearly. Start with observations, then explain using chemical theory.

Step 1: Describe the trend

"The concentration decreases rapidly at first, then more slowly."

Step 2: Explain with theory

"This follows first-order kinetics where rate depends on concentration."

Step 3: Connect to context

"As concentration decreases, fewer collisions occur, reducing reaction rate."

Sharpen Your Chemistry Skills

With Study Marker, you can generate quizzes from syllabus dot points and practise applying them to new data.

Practice applying chemical concepts to different data sets and scenarios.

Final Thought

Data-based questions are about thinking like a scientist. Practise spotting patterns, linking to theory, and structuring your answers clearly.

Remember: Data analysis in chemistry is about connecting observations to underlying principles. The data tells a story — your job is to explain that story using chemical theory.

IB Chemistry: How to Master Data-Based Questions