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

It is notorious that the same discovery is frequently made simultaneously and quite independently, by different persons...it...It is notorious that the same discovery is frequently made simultaneously and quite independently, by different persons...it would seem that discoveries are usually made when the time is ripe for them - that is to say when the ideas from which they naturally flow are fermenting in the minds of many men.

Francis Galton (1822 - 1911)
Francis Galton (1822 - 1911)
InThinking

Supporting international schools with high quality PD & interactive online resources

Dynamic
Creative
Personal
About us
Visit our hub website

Recommendations

See all
"The resources available for both teachers and students on this website are remarkable. They are organized, user-friendly and topical. My student feedback was that they found all the material worthwhile and appreciated the access. I was evident to me..."

Veronica Riffle

International School of Prague, s.r.o.

"Hi fellow chemistry teachers. I am leaving IB this year but ABSOLUTELY recommend that you lobby your coordinators and administrators to get access to this site. It is something I wish i had done/been aware of and done YEARS ago. Geoff makes things easily..."

Jeff Hinton

Greengate 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