Textbooks

General Chemistry Textbooks for Local and National Exams

• Chemistry, 10th Edition (with challenging integrated practice problems)

by Steven S. Zumdahl,‎ Susan A. Zumdahl,‎ and Donald J. DeCoste

• Chemistry: The Central Science, 13th Edition

by Theodore E. Brown,‎ H. Eugene LeMay,‎ Bruce E. Bursten,‎ Catherine Murphy,‎ Patrick Woodward,‎ Matthew E. Stoltzfus

• Chemistry: The Molecular Nature of Matter and Change, 8th Edition

by Martin Silberberg,‎ Patricia Amateis

• Chemical Principles: The Quest for Insight, 7th Edition (with challenging integrated sample problems)

by Peter Atkins,‎ Loretta Jones,‎ and Leroy Laverman

• General Chemistry: Principles and Modern Applications, 10th Edition (challenging EOC problems)

by Ralph H. Petrucci, F. Geoffrey Herring, Jeffry D. Madura, Carey Bissonnette

A few textbooks used for UK Chemistry Olympiad

• Chemistry3 - Introducing Inorganic, Organic and Physical Chemistry

By Andrew Burrows, John Holman, Andrew Parsons, Gwen Pilling, Gareth Price · 2017

Student Resources (brief organic chemistry for local and national)

• Chemical Structure and Reactivity - An Integrated Approach

By James Keeler, Peter Wothers · 2013

Resources

• UKChO Round 2 Guidance

Organic Chemistry Textbooks for Study Camp and IChO

• Organic Chemistry, 2nd Edition

by David R. Klein

• Organic Chemistry, 2nd Edition

by Jonathan Clayden,‎ Nick Greeves,‎ and Stuart Warren

• The Art of Writing Reasonable Organic Reaction Mechanisms, 2nd Edition

by Robert B. Grossman (website of the author with errata and answer key for all problems)

• 演習で学ぶ有機反応機構―大学院入試から最先端まで - 化学同人

by Fukuyama

Free Online Chemistry Textbooks

• Chemistry by OpenStax (PDF)
• Open-access Chemistry Textbooks by LibreTexts Library
• Introduction to Inorganic Chemistry by wikibooks
• 有机化合物命名原则2017 - 科学出版社

Textbooks Recommended by Others

1. A comparison between several general chemistry textbook for chemistry olympiad by a formal IChO medalist.
2. Textbook recommended by WW-P ISO Club.
3. 有什么比较好的化学书籍推荐？ - 知乎回答
4. List of good texts to end all textbook questions from Chemistry Olympiad Study Group (facebook)

List of good texts to end all textbook questions:

General Chemistry

-Atkins Chemical Principles (terrible and boring but has lots of info)

-Zumdahl Chemical Principles (has good practice problems)

Organic Chemistry

-Klein Organic Chemistry (best book to self-teach orgo, fun to read)

-Carey Organic Chemistry (shitty book but used at USNCO camp)

-Clayden Organic Chemistry (intermediate level orgo book, good supplement to Klein)

-Grossman The Art of Writing Reasonable Organic Reaction Mechanisms (great little book to get better at writing mechanisms)

-Claridge High-Resolution NMR Techniques in Organic Chemistry (most stuff in here is too advanced for Olympiad but it is a good NMR reference)

Physical Chemistry

-McQuarrie Physical Chemistry (no p chem book can even compare)

-Griffiths Intro to Quantum Mechanics (good reference)

Inorganic Chemistry

-Miessler Inorganic Chemistry (okay, not that fun to read)

-Housecroft Inorganic Chemistry (great inorganic book)