# Alkali

A base that dissolves in water and forms hydroxide ions (OH-). Alkalis have a pH above 7 and feel soapy.

Chemistry (school) · Part 06: Acids, bases and salts · Card 2 of 9 · Last updated 2026-10-19

## Analogy

If acids hand out H+, alkalis supply OH- that grabs those H+ and takes them out of play.

## In practice

Sodium hydroxide is in oven cleaner. Bleach and soap are also alkaline.

## Practice

### Flashcards

- **What ion do alkalis produce in water?** Hydroxide ions, OH-.

## Questions people ask

### Why do alkalis feel soapy?

Alkalis react with the oils in your skin and turn them into a kind of soap. That slippery feeling is a sign your skin is being attacked. Strong alkalis such as sodium hydroxide are corrosive and can burn skin, so never touch them to test.

### Which common household items are alkaline?

Bleach, soap, oven cleaner, baking soda and toothpaste are alkaline. Indigestion tablets are bases that neutralise stomach acid. Their pH is above 7. Farmers also spread lime, a base, on acidic soil to raise its pH so crops grow better.

Web page: https://studyvisually.com/learn/science/chemistry-school/chemistry-school-part-6/chemistry-school-part-6-concept-2
Study this card in the app: https://studyvisually.com/app/learn?category=chemistry-school&card=chemistry-school-part-6-concept-2