pH
Leaving Cert Chemistry · Interactions of Matter
Higher Level
A measure of how acidic or basic a solution is, defined as the negative logarithm to base ten of the hydrogen ion concentration in moles per litre. At 25 degrees Celsius a value of 7 is neutral, lower values are acidic and higher values are basic.
Ordinary Level
A scale that shows how acidic or basic a solution is, usually running from 0 to 14. Below 7 is acidic, 7 is neutral and above 7 is basic.
Chemistry practice is part of Pro. Reading the definitions here is always free.
More Interactions of Matter terms
Get the free study guide
H1 Owl is now on the App Store: download it for iPhone. Sign up here and get The Leaving Cert Maths Game Plan, our free PDF study guide, straight away, plus occasional study tips.
Occasional emails, no spam. Under 16? Ask a parent to sign up for you.
Where next
All Chemistry terms
The whole Leaving Cert Chemistry glossary, grouped by strand and labelled by level.
Browse ChemistryQuestion of the day
One real Higher Level Maths question, new every day, with the explanation.
Answer today'sThe app
1,700+ original questions across Maths, Biology, Chemistry and Physics. Maths is free.
See the app