Chemistry at A-Level covers a much wider range of topics compared to what is taught at O-Level, and involves a deeper exploration of the content as well. The syllabus is designed to place less emphasis on factual material and greater emphasis on the understanding and application of scientific concepts and principles. Experimental work is also an important component. Students will need to be able to understand the nature of scientific knowledge, demonstrate science inquiry skills and relate science and society, which are the practices of Science.


1) What is the difference between H1 and H2 Chemistry?

The content covered in H1 is significantly less compared to the content covered in H2. There is NO lab work /SPA exam for H1. Please refer to for more information.

Comparison of Subject Content in H1 and H2 Chemistry

Core Ideas




Atomic Structure

Structure and Properties

Chemical Bonding

The Gaseous State


Theories of Acids and Bases

Theories of Acids and Bases

The Periodic Table/Period 3

Group 2

Group 1

Group 17

Group 17 (less)


The Mole Concept and Stoichiometry (including Redox reactions)

The Mole Concept and Stoichiometry (including Redox reactions)

Chemical Energetics

 Chemical Energetics

(less content compared to H2)

Reaction Kinetics

Reaction Kinetics (less)

Chemical Equilibria

Chemical Equilibria (less)

Chemistry of Aqueous Solutions

Acid-Base Equilibria

Theories of Acids and Bases (continued) (less)

Solubility Equilibria


Organic Chemistry


Extension Topics


(includes some aspects of Organic Chemistry that are related to polymers. Content is very much reduced.)



Halogen Derivatives

Hydroxy Compounds


Carbonyl Compounds

Carboxylic Acids and Derivatives

Nitrogen Compounds



An Introduction to The Chemistry of Transition Elements



Frequent practical sessions


2) What is H3 Chemistry?

H3 Chemistry is a subject that is only offered to students who have done relatively well at the end of the first year. It allows you to explore Chemistry in greater depth, with the focus on applications.

3) I took Combined Science at O-Level. Will I be able to cope with H1/H2 Chemistry?

A-Level Chemistry does build upon your knowledge of O-Level Chemistry. However, performance is largely dependent on your consistency and effort as you study the subject.

As a Combined Science student, you have not covered Electrolysis and Metallic Bonding, as well as major concepts in Energy from Chemicals, Kinetics (Chemical Reactions), and structures of covalent compounds, which have been covered in Pure Chemistry.

Many other topics are new and all students start on an equal footing.

4) What is the assessment format for H1 / H2 Chemistry?
In addition to the lack of Practical Exams for H1 Chemistry, the assessment for H1 and H2 Chemistry also differs as shown below:


H2 (%)

H1 (%)


30 MCQs (15%)

30 MCQs (33%)


Structured Qns
[including Data-Based] (30%)

Section A: Structured Qns

[including Data Response Qn(s)]

Section B: Free Response Qns



Free Response Qns  (35%)



Practical Paper (20%)


Assessment Objectives




Knowledge with understanding




Handling, applying and evaluating information




Experimental skills and investigations



5) What is the assessment format for H3 Chemistry?
Students will need to answer free response questions (at least 4) in 2 h 30 min, including 1 or 2 stimulus-based questions.

6) Which courses in university has A-Level Chemistry as admission criteria?

A good H2 pass in Chemistry is required for courses such as Medicine, Dentistry (these 2 courses also require another H2 Science), Pharmacy, Food Science and Technology, Chemical Engineering, Environmental Engineering and Chemistry.

The list given is not exhaustive, and for most courses that requires knowledge of Science, at least one H2 science (not necessarily Chemistry) may be required. E.g. H2 Chemistry or H2 Physics for Engineering

7) Should I pursue A-Level Chemistry?
Individuals will have to decide and take ownership of their choices. Ultimately, the ideal scenario is that either you enjoy learning about Chemistry at a much greater depth compared to O-Level, or you require A-Level Chemistry for admission to certain University Courses.