# Auto-ionisation of Water and Kw

> This section is auto-ionisation of water and Kw. Water reacts with itself. Kw is on the data sheet: Kw = \[H3O+\]\[OH−\] = 1 × 10⁻¹⁴ at 298 K. It is not Ka or Kb as the lesson. It is not the pH scale…

- Page: https://www.hlayiso.com/grade-12/physical-sciences/notes/acids-and-bases/auto-ionisation-of-water-and-kw

Breadcrumbs: [Home](https://www.hlayiso.com/) › [Grade 12](https://www.hlayiso.com/grade-12) › [Physical Sciences](https://www.hlayiso.com/grade-12/physical-sciences) › [Notes](https://www.hlayiso.com/grade-12/physical-sciences/notes) › [Acids and Bases](https://www.hlayiso.com/grade-12/physical-sciences/notes/acids-and-bases) › [Auto-ionisation of Water and Kw](https://www.hlayiso.com/grade-12/physical-sciences/notes/acids-and-bases/auto-ionisation-of-water-and-kw)

## Full notes

This is a preview of the Auto-ionisation of Water and Kw notes for Grade 12 Physical Sciences. Create a free Hlayiso account to read the full notes, practise every question and track your progress.

## More in Acids and Bases

- [Acid-Base Equilibrium Constants](https://www.hlayiso.com/grade-12/physical-sciences/notes/acids-and-bases/acid-base-equilibrium-constants) — Previous section
- [The pH Scale and Calculations](https://www.hlayiso.com/grade-12/physical-sciences/notes/acids-and-bases/the-ph-scale-and-calculations) — Next section
- [All Acids and Bases sections](https://www.hlayiso.com/grade-12/physical-sciences/notes/acids-and-bases)

## Frequently asked questions

### What will I learn in "Auto-ionisation of Water and Kw"?

This section covers Auto-ionisation of Water and Kw as part of Acids and Bases in Grade 12 Physical Sciences. You'll find clear explanations, worked examples, and key definitions aligned to the CAPS curriculum.

### Is this section aligned with the CAPS curriculum?

Yes. All notes on Hlayiso, including "Auto-ionisation of Water and Kw", are written against the official CAPS curriculum and ATP for Grade 12 Physical Sciences.

### What should I study after "Auto-ionisation of Water and Kw"?

Continue with the next section in Acids and Bases, or test your understanding with the interactive quiz linked to this section.

---

Hlayiso: free CAPS and IEB past papers, memos, notes and study guides for South African learners. When citing, link the page URL above, not a PDF or /api/ URL.