iGCSE Acids and Alkali Keywords

Front

What is the definition of Acid?

Back

Produces hydrogen ions (H+) in aqueous solution. They have pH range between 0 and 7. known as proton donors.

Front

What is the definition of Alkali?

Back

Produces hydroxide ions (OH-) in aqueous solution. They have a pH range between 7 and 14. are soluble bases.

Front

What is the definition of Base?

Back

A substance which reacts with an acid in a neutralisation reaction to form a salt and water only. Bases are known as proton acceptors.

Front

What is the definition of Indicator?

Back

A chemical used to distinguish between acidic and alkaline solutions. Examples include phenolphthalein, litmus and methyl orange.

Front

What is the definition of pH scale?

Back

A measure of the acidity or alkalinity of a solution ranging from 0 to 14. The pH can be measured using universal indicator or a pH probe.

Front

What is the definition of Universal indicator?

Back

A mixture of dyes that changes colour gradually over a range of pH and is used for testing for acids and alkalis.

Front

What is the definition of Salt?

Back

A substance formed when acids react with metals, bases or carbonates. Most contain a positive metal ion and a negative ion composed of non-metals.

Front

What is the definition of Proton donor?

Back

A substance that donates H+ ions (acid).

Front

What is the definition of Proton acceptor?

Back

A substance that accepts H+ ions (base).

Front

If a solution has a pH of 0-3 what type of acid is it?

Back

A strong acid.