Revision Notes MCQ Bank SAQ Bank Study Cards Courses Teachers Blog
OCR A Level Chemistry A – Module 2 Foundations in Chemistry

2.1.2
Compounds, Formulae and Equations

Section 2.1.2 covers writing the formulae of ionic compounds from ionic charges and constructing balanced full and ionic equations with state symbols, for reactions studied and for unfamiliar reactions. These pages cover the ionic formulae and the equations.

Exam Paper
Paper 1 & 2
H432/01 and H432/02
Specification Points
2.1.2 (a) – (b)
2 learning outcomes
Sub-topics
2 lessons
Equations and Reaction Types
Exam Board
OCR
H432 (2015 onwards)

Revision Notes

2 revision notes, in the order the specification teaches them.

A level balance with the same atoms in each pan
1

Equations and Reaction Types

Writing and balancing full equations with state symbols, ionic equations, and the typical reactions of acids (2.1.2 (b)).

Start revising
Ions fitting together in the right ratio
2

Ions and Ionic Formulae

Predicting ion charges from the Periodic Table, the seven named ions and constructing ionic formulae (2.1.2 (a)).

Start revising

Summary Map

Download, print and revise the key facts of this topic at a glance.

Summary map

Download, print and revise the key facts of this topic at a glance.

Illustration of a summary map: compounds joined by reaction arrows
Summary map · PDF

Formulae and Equations Map

OCR A Level Chemistry A · 2.1.2 Compounds, formulae and equations

The whole of 2.1.2 on one A4 page: ion charges, the ions to learn, balancing, state symbols, ionic equations and unfamiliar reactions.

Download the map6 key ideas + an equations table · A4 portrait · print ready

© 2026 Online Learning System. For personal study: printing is allowed; editing, copying and redistribution are not.

Virtual Lessons

Recorded video lessons that teach the topic step by step.

Coming soon

The Virtual Lessons for 2.1.2 Compounds, Formulae and Equations are being recorded.

MCQ Bank

Multiple-choice papers on this topic, marked the moment you submit.

Coming soon

The MCQ papers for 2.1.2 Compounds, Formulae and Equations are being written.

Open the MCQ Bank

SAQ Bank

Written, drawn and worked exam practice on this topic.

Coming soon

The exam practice papers for 2.1.2 Compounds, Formulae and Equations are being written.

Open the SAQ Bank

Revision Game

Match reagents to products, with your board's reagents and conditions.

Coming soon

The revision game for 2.1.2 Compounds, Formulae and Equations is being built.

Study Cards

Pick a deck, then turn each card to check what you remember.

Specification

Every specification point in this topic, in the exam board's own words. Rate how confident you are with each one.

Official OCR documentsSpecification (opens the OCR website in a new tab)Data sheet (opens the OCR website in a new tab)

Self-assessment · 12 points

Sign in to rate how confident you feel about each point. Your ratings are saved to your account, follow you to any device, and appear beside your KASP analytics, kept apart from your marks.

Sign in to rate yourself
0 Confident0 Getting there0 Not yet12 Not rated

2.1.2

  1. a

    the writing of formulae of ionic compounds from ionic charges

    Revise
  2. a (i)

    prediction of ionic charge from the position of an element in the periodic table

    Revise
  3. a (ii) a

    recall of the name and formula for the nitrate ion, NO3–

    Revise
  4. a (ii) b

    recall of the name and formula for the carbonate ion, CO32–

    Revise
  5. a (ii) c

    recall of the name and formula for the sulfate ion, SO42–

    Revise
  6. a (ii) d

    recall of the name and formula for the hydroxide ion, OH–

    Revise
  7. a (ii) e

    recall of the name and formula for the ammonium ion, NH4+

    Revise
  8. a (ii) f

    recall of the name and formula for the zinc ion, Zn2+

    Revise
  9. a (ii) g

    recall of the name and formula for the silver ion, Ag+

    Revise
  10. b i

    construction of balanced chemical equations, including state symbols, for reactions studied

    Revise
  11. b ii

    construction of balanced ionic equations, including state symbols, for reactions studied

    Revise
  12. b iii

    construction of balanced chemical equations (including ionic equations), including state symbols, for unfamiliar reactions given appropriate information

    Revise