Chemistry · XCH11 / YCH11

How International A level Chemistry works

Start here: the units, their exam codes and when you can sit them for Pearson Edexcel International AS and A level Chemistry.

Two qualifications in one course

International A level Chemistry is modular: you sit it unit by unit.

The International AS (cash-in code XCH11) is Unit 1, Unit 2, Unit 3. It is a qualification on its own.
The full International A level (cash-in code YCH11) is all 6 units: the AS units plus Unit 4, Unit 5, Unit 6.

You can bank AS results in Year 12 and add the A2 units in Year 13.

The units

Each unit has its own exam code. These are the codes your exams officer uses to enter you.

Unit	Code	Title	Level	Exam series 2026/27
Unit 1	WCH11	Structure, Bonding and Introduction to Organic Chemistry	AS	October, January and June
Unit 2	WCH12	Energetics, Group Chemistry, Halogenoalkanes and Alcohols	AS	October, January and June
Unit 3	WCH13	Practical Skills in Chemistry I	AS	October, January and June
Unit 4	WCH14	Rates, Equilibria and Further Organic Chemistry	A2	October, January and June
Unit 5	WCH15	Transition Metals and Organic Nitrogen Chemistry	A2	October, January and June
Unit 6	WCH16	Practical Skills in Chemistry II	A2	October, January and June

Source: Pearson Information Manual 2026/2027, International A level

When you can sit them

Pearson runs International A level exams in January, May to June and October, but not every unit is offered in every series. Plan your units with your teacher, and always confirm entries with your exams officer: Pearson updates the manual every year.

Worked example

You finish Year 12 having sat the AS units in Chemistry. What can you claim?

The AS units are Unit 1, Unit 2, Unit 3.
Together they give the International AS (XCH11).

Answer: The International AS in Chemistry (XCH11); add the A2 units in Year 13 for the full A level (YCH11).

Key idea: International AS Chemistry = Unit 1, Unit 2, Unit 3 (XCH11). Full International A level = all 6 units (YCH11). Not every unit is offered in October.

Check yourself

What is the cash-in code for the full International A level in Chemistry?
- XCH11
- ZCH11
- YCH11
- WCH11
Show answer
YCH11. YCH11 is the full International A level; XCH11 is the International AS.
Which code is the International AS in Chemistry?
- XCH11
- YCH11
- WCH11
- QCH11
Show answer
XCH11. XCH11 is the International AS cash-in code.
How many units make up the full International A level in Chemistry?
Show answer
6. The full A level is 6 units: Unit 1, Unit 2, Unit 3, Unit 4, Unit 5, Unit 6.
In 2026/27, in which exam series can you sit Chemistry Unit 1 (Structure, Bonding and Introduction to Organic Chemistry)?
- January and June only
- October, January and June
- June only
- January only
Show answer
October, January and June. Pearson's 2026/27 manual lists Unit 1 as available in: October, January and June.
Which Chemistry unit has the code WCH12?
- Unit 1
- Unit 3
- Unit 4
- Unit 2
Show answer
Unit 2. WCH12 is Unit 2: Energetics, Group Chemistry, Halogenoalkanes and Alcohols.

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Sources

Last updated 7 November 2026. Spotted a mistake? Email alevel@lifereadysociety.com.