Chemical AnalysisAQA

Purity & Formulations

Revise Purity & Formulations in Chemical Analysis for GCSE Chemistry with 22 exam-style questions and 12 flashcards. Use the notes, sample questions, and flashcards below to connect this topic to the rest of your GCSE revision plan.

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The Purity Paradox

Introduction 2

What Makes a Substance Pure?

Deep Dive 3

Melting and Boiling Points as Purity Tests

Deep Dive 4

Paper Chromatography — Interactive Diagram

Diagram 5

Why Impurities Affect Melting Points

How It Works 6

Key Definitions

Definitions 7

Formulations

Key Facts 8

Pure vs Impure: Everyday Examples

Comparison 9

Common Misconceptions

Misconceptions 10

Memory Aid

Memory Aid 11

Exam Focus

Exam Focus 12

Exam Tips for Purity and Formulations

Exam Tips 13

Knowledge Organiser: Purity and Formulations

Summary

Sample Flashcards

What is a formulation?

A mixture designed to have specific properties for a particular purpose, with each component in measured quantities

Give 3 examples of formulations

1) Paint (pigment + binder + solvent), 2) Medicine tablets (active ingredient + binder + filler), 3) Petrol (hydrocarbons + octane improvers + additives)

Exam questions for Purity & Formulations

In chemistry, what does it mean for a substance to be described as 'pure'?

A. It contains only one type of element or compound
B. It has been filtered to remove large particles
C. It has no colour or smell
D. It is safe to drink or eat

1 markfoundation

Explain why the presence of impurities in a substance lowers its melting point and causes it to melt over a range of temperatures.

3 marksstandard

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