9701 AS Chemistry/ Topic 13 Introduction to organic chemistry/ 5 interactive simulations/ drag to rotate 3D scenes

Organic chemistry, made interactive

Five simulations covering Topic 13: the five ways of writing a formula beside the real 3D shape, building a molecule and reading its systematic name, the three kinds of structural isomerism, cis-trans and optical stereoisomerism you can try to superimpose, and how bonds break with curly arrows.

1. Five ways to write the same molecule 3D · 13.1

Empirical, molecular, structural, displayed and skeletal: each formula throws away a little more detail. Pick a compound and see all five beside the real three-dimensional shape.

drag to rotate · wheel to zoom

Compound

2. Build a molecule, read its name 2D · 13.2

Choose the longest chain, the functional group and where the branches go. The name assembles itself in front of you, so you can see exactly which part of the name comes from which part of the molecule.

Main chain

Functional group

Group on carbon1

Methyl branches

NAME

3. Structural isomerism 3D · 13.3

Same molecular formula, different structure. There are three kinds: the chain can be branched differently, the group can sit on a different carbon, or the atoms can make an entirely different functional group. Flip between the isomers and compare.

drag to rotate

Type

Isomer

MOLECULAR FORMULA

NAME

BOILING POINT

ISOMERISM

4. Stereoisomerism: cis-trans and optical 3D · 13.3

Same atoms joined in the same order, but arranged differently in space. A C=C cannot rotate, so the groups are locked cis or trans. A carbon with four different groups has a non-superimposable mirror image. Try to superimpose them.

drag to rotate · use the buttons to try to superimpose

Type

CONDITION

SUPERIMPOSABLE?

5. Breaking bonds: radicals, nucleophiles and electrophiles 2D · 13.4

A covalent bond can break two ways. Split the pair evenly and you get radicals; take both electrons to one side and you get ions. Curly arrows show where the electrons go: a full arrow for a pair, a half arrow for a single electron.

Show

TheLucidSTEM · Cambridge International AS Level Chemistry 9701 · Topic 13 Introduction to organic chemistry. Every scene runs in the browser; drag to rotate 3D scenes, wheel to zoom. Values are standard textbook data rounded for teaching.

About this lab: Introduction to organic chemistry

Empirical, molecular, structural, displayed and skeletal formulae for the same molecule side by side, an IUPAC naming machine that builds the name from the chain, the functional group and its position, chain, position and functional group isomerism in 3D, cis-trans and optical stereoisomerism with a rotatable pair of enantiomers, and curly arrows for homolytic and heterolytic fission.

Introduction to organic chemistry is a free, browser-based simulation for Cambridge International AS & A Level Chemistry 9701 (topic 13 An introduction to AS Level organic chemistry). The same ideas are examined in Cambridge IGCSE Chemistry 0620 (topic 11 Organic chemistry). The course is assessed in Paper 1 (Multiple Choice (AS)), Paper 2 (AS Structured), Paper 3 (Advanced Practical), Paper 4 (A Level Structured), Paper 5 (Planning, Analysis, Evaluation). Syllabus for examination in 2025-2027. There are 5 tabs, each a self-contained experiment with its own controls and live readings, and nothing to install: it runs on a laptop, tablet or classroom projector.

Syllabus coverage

13.1 Formulae, functional groups and the naming of organic compounds. Lessons: Organic formulae and functional groups, Naming organic compounds.
13.2 Characteristic organic reactions. Lessons: Types of organic reaction and mechanism.
13.3 Shapes of organic molecules; σ and π bonds. Lessons: Shapes of organic molecules, sigma and pi bonds.
13.4 Isomerism: structural and stereoisomerism. Lessons: Structural isomerism, Cis-trans and optical isomerism.

Full syllabus map: AS Level Chemistry 9701 topic 13.

How to use this simulation

1. Five ways to write the same molecule. Empirical, molecular, structural, displayed and skeletal: each formula throws away a little more detail.
2. Build a molecule, read its name. Choose the longest chain, the functional group and where the branches go.
3. Structural isomerism. Same molecular formula, different structure.
4. Stereoisomerism: cis-trans and optical. Same atoms joined in the same order, but arranged differently in space.
5. Breaking bonds: radicals, nucleophiles and electrophiles. A covalent bond can break two ways.
The buttons at the end of the tab strip give the scene the whole window (Full screen, Hide controls) and, on a dark stage, a projector-friendly palette (Light scene). Many scenes also have drag handles: drag them to change the set-up directly.

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