Home of real teaching & learning
  • Full support for teachers
  • Focus on critical thinking
  • Engaging classroom activities
  • Integrated student eBook
  • Assessed tasks / qBank
  • Practice exam questions
Find out more Download brochure

The InThinking Guarantee: Our sites are written by expert practitioners and not by AI

See our AI policy

Disclaimer: InThinking subject sites are neither endorsed by nor connected with the International Baccalaureate Organisation.

Don't miss out, find out!
Recommendations
Read what users are saying about the site.
Site authors
Geoffrey Neuss
Read Geoffrey's Bio
Geoffrey
Paul
IB Approved Workshops
Chemistry
IB DP Category 2

Barcelona, Spain, 12 - 14 February 2027

Find out more
Chemistry: A focus on the experimental programme
IB DP Category 3

Paris, France, 19 - 21 February 2027

Find out more
Virtual Think-Ins
Focus On: IB Teaching – A Practical Guide for Teachers new to the IB

20 November 2026

Find out more
InThinking Shorts
Getting the most out of InThinking Subject Sites

12 October 2026

Find out more
Getting the most out of InThinking Subject Sites

15 October 2026

Find out more
Chemistry: Getting the most out of the site

4 November 2026

Find out more

Find all InThinking events at
inthinking.net

Quote of the day

The ingenuity and logic that enabled chemists to determine complex molecular structures from the number of isomers, the reactivity of the molecule, and of its fragments, the freezing point, the empirical formula, the molecular weight, etc., is one of the outstanding triumphs of the human mind.

Henry Eyring (1901 - 1981)
Henry Eyring (1901 - 1981)
InThinking

Supporting international schools with high quality PD & interactive online resources

Dynamic
Creative
Personal
About us
Visit our hub website

Recommendations

See all
"This is my go to resource for teaching IB HL Chemistry. I have been teaching for the past 19 years and I can say this is by far the best resource that I have ever taught with. The website taught me how to efficiently teach with the most clarity. My IB..."

Neil Corrigan

St Edward High School

"I have used InThinking for many years and have found it an invaluable source of information for all things IB Chemistry. Geoff is a legend in the world of IB Chem and is both supportive and quick to respond to all queries. I would advocate InThinking..."

James Midgley

Australian Internatonal School

Subscriber comments

See all

  • Geoffrey

    Site author
    5 Oct 2026

    Hello Harprit, R2.3.4 gives X(g) ⇌ X(aq) as an example so I guess students could be asked to explain why a bottle of carbonated water fizzes when the top is removed from the bottle and then eventually goes flat if the top is left off.

    R2.3 The extent of chemical change

  • Harprit

    5 Oct 2026

    Hello Geoff, In R2.3.4, the IB guide talks about Le Chatelier's Principle to physical equilibria and gives a (g) / (aq) as an example. A very old IB question came up looking at a (l) / (g), and what happens when you increase the volume of liquid....

    R2.3 The extent of chemical change

  • Paul

    Site author
    1 Oct 2026

    Me too! As far as I know, there are no other issues with sodium hydroxide in the burette. My students frequently do it that way round. We just make sure that we don't leave the sodium hydroxide in the burette, and we rinse it out afterwards. The etching...

    Acid-alkali titration

  • Austin

    30 Sep 2026

    In general, I find it easier to identify the colourless to pink colour change rather than pink to colourless.  Is there any major issue with switching the acid and base other than that the sodium hydroxide may cause etching or other damage to...

    Acid-alkali titration

Help