alkali: meaning, definition, pronunciation and examples

C1
UK/ˈæl.kəl.aɪ/US/ˈæl.kə.laɪ/

Technical, Scientific, Academic, Some everyday use (e.g., cleaning products).

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Quick answer

What does “alkali” mean?

A water-soluble base that neutralizes acids, typically having a bitter taste and giving a soapy, slippery feel in solution.

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Pronunciation

Definition

Meaning and Definition

A water-soluble base that neutralizes acids, typically having a bitter taste and giving a soapy, slippery feel in solution.

Any substance with basic (high pH) chemical properties; in geology, soils or minerals rich in soluble salts, especially of sodium or potassium. Informally, something that counteracts acidity.

Dialectal Variation

British vs American Usage

Differences

Spelling and pronunciation are standard. No significant usage difference, though UK 'chemistry' and US 'chemistry' syllabi may introduce the term at slightly different stages.

Connotations

Neutral/scientific in both. In gardening/agriculture, 'alkaline soil' is more common than 'alkali soil' in everyday UK English.

Frequency

Equally low-frequency in general discourse, but standard in scientific/technical contexts in both varieties.

Grammar

How to Use “alkali” in a Sentence

Alkali + noun (alkali metal, alkali solution)Adjective + alkali (strong alkali, volatile alkali)Verb + alkali (neutralise the alkali, react with an alkali)

Vocabulary

Collocations

strong
strong alkalicaustic alkalialkali metalalkali soil
medium
alkali solutionconcentrated alkalireact with alkalialkali content
weak
alkali resistancetreat with alkalialkali attackalkali leaching

Examples

Examples of “alkali” in a Sentence

verb

British English

  • [No standard verb form. 'Alkalise' is the related verb.]

American English

  • [No standard verb form. 'Alkalize' is the related verb.]

adverb

British English

  • [No standard adverb form derived directly from 'alkali'. 'Alkaline' is not used as an adverb.]

American English

  • [No standard adverb form derived directly from 'alkali'. 'Alkaline' is not used as an adverb.]

adjective

British English

  • The soil was far too alkaline for the rhododendrons to thrive.
  • They tested the lake's alkaline water.

American English

  • The soil was way too alkaline for the blueberries to grow.
  • They analyzed the pool's alkaline levels.

Usage

Meaning in Context

Business

Rare, except in chemical manufacturing, cleaning product industries, or agricultural reports (e.g., 'alkali soils reduce crop yield').

Academic

Common in chemistry, geology, environmental science, and engineering texts.

Everyday

Limited to contexts like gardening (soil pH), swimming pool maintenance, or household cleaning products (e.g., 'this cleaner contains alkalis').

Technical

The primary domain. Precise use in chemistry labs, industrial processes, soil science, and metallurgy.

Vocabulary

Synonyms of “alkali”

Strong

base (in chemistry)lye (specifically sodium or potassium hydroxide)

Neutral

baseantacid (in specific contexts)caustic (for strong alkalis)

Weak

alkaline substancebasic compound

Vocabulary

Antonyms of “alkali”

acidacidic compound

Watch out

Common Mistakes When Using “alkali”

  • Mispronouncing as /ælˈkɑː.li/ (alkah-lee).
  • Using 'alkaline' and 'alkali' interchangeably as nouns (Alkali is the substance, alkaline is the adjective).
  • Confusing 'alkali' (soluble base) with 'base' (broader category). All alkalis are bases, not all bases are alkalis.

FAQ

Frequently Asked Questions

In chemistry, all alkalis are bases, but not all bases are alkalis. An alkali is specifically a base that is soluble in water (e.g., sodium hydroxide). Insoluble bases like copper(II) oxide are not alkalis.

Lye is a common name for a strong alkali, specifically sodium hydroxide (NaOH) or potassium hydroxide (KOH). So, lye is a type of alkali, but 'alkali' is the broader category.

Yes. Baking soda (sodium bicarbonate), washing soda (sodium carbonate), and household ammonia solutions are common, milder alkalis found in homes. Oven cleaners often contain stronger alkalis like sodium hydroxide.

It refers to soil with a high pH (above 7) and often a high concentration of soluble salts, like sodium carbonate. This can be toxic to many plants and is a challenge in agriculture, especially in arid regions.

A water-soluble base that neutralizes acids, typically having a bitter taste and giving a soapy, slippery feel in solution.

Alkali is usually technical, scientific, academic, some everyday use (e.g., cleaning products). in register.

Alkali: in British English it is pronounced /ˈæl.kəl.aɪ/, and in American English it is pronounced /ˈæl.kə.laɪ/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

  • [No common idioms for 'alkali' as a standalone word]

Learning

Memory Aids

Mnemonic

Think: 'All allies neutralize acids.' Alkali sounds like 'ally,' and alkalis are bases that counteract (are allies against) acids.

Conceptual Metaphor

ALKALI IS A NEUTRALIZING AGENT / COUNTER-FORCE (e.g., 'The alkali acted to calm the acidic reaction').

Practice

Quiz

Fill in the gap
To safely clean the drain, she used a mild like washing soda, not a harsh acid.
Multiple Choice

Which of the following is NOT a characteristic property of a typical alkali?