Year 9 Chemical Reactions, Acids and Bases

Vocabulary practice flashcards for Year 9 chemistry covering chemical reactions, conservation of mass, signs of chemical change, acids, bases, indicators, pH scale, and neutralisation reactions.

Reactants

The substances present at the beginning of a chemical reaction, listed before the arrow in a word equation.

Products

The new substances formed as a result of a chemical reaction, listed after the arrow in a word equation.

Law of Conservation of Mass

A scientific law stating that matter cannot be created or destroyed in any chemical reaction, meaning the mass of the products equals the mass of the reactants.

Physical Change

A change that occurs without altering the chemical nature or identity of a substance, meaning no new substances are formed.

CFARTS

A mnemonic for remembering the signs of a chemical reaction: Colour change, Formation of gas, Aroma, Rearrangement, Temperature change, and formation of Solid.

AGAPE

A mnemonic for signs of a chemical reaction representing Altered molecules, Gas formed, Aroma colour changes, Precipitate formed, and Energy released or absorbed.

Acid

A substance that tastes sour, has a pH less than $7$, turns litmus red, and forms hydrogen ions ($H^+$) in water.

Base

A substance that tastes bitter, has a pH greater than $7$, turns litmus blue, and forms hydroxide ions ($OH^-$) in water.

Alkali

A base that dissolves in water.

Indicator

A substance that changes colour to show whether a solution is an acid or a base.

Universal Indicator

A mixture of indicators that gives a range of colours to show the relative strength or specific pH level of an acid or base.

pH Scale

A scale ranging from $0$ to $14$ used for measuring the relative acidity or basicity of a substance, where $7$ indicates neutral.

Neutralisation

A chemical reaction between an acid and a base that produces a salt and water.

Pop Test

A test used to confirm the presence of hydrogen gas.

Acid + Metal Reaction

A chemical reaction in which an acid reacts with a metal to produce a salt and hydrogen gas.

Acid + Carbonate Reaction

A chemical reaction in which an acid reacts with a carbonate to produce a salt, water, and carbon dioxide gas.

Hydrochloric Acid Salt Name

The second part of the salt name formed when hydrochloric acid is used in a neutralisation reaction, which is 'chloride'.

Sulphuric Acid Salt Name

The second part of the salt name formed when sulphuric acid is used in a neutralisation reaction, which is 'sulphate'.

Nitric Acid Salt Name

The second part of the salt name formed when nitric acid is used in a neutralisation reaction, which is 'nitrate'.