Chemical Reactions, Acids, Bases, Metals, and Carbon Compounds Vocabulary

A set of vocabulary flashcards covering chemical reactions, acids, bases, salts, metals, non-metals, and carbon compounds based on practical science activities.

Quicklime

Calcium oxide ($CaO(s)$), a compound that reacts vigorously with water in an exothermic combination reaction to form slaked lime.

Slaked Lime

Calcium hydroxide ($Ca(OH)_2(aq)$), the product formed when quicklime reacts with water with the evolution of heat.

Thermal Decomposition Reaction

A decomposition reaction activated by heat, such as the breakdown of hydrated green ferrous sulphate ($FeSO_4 \cdot 7H_2O$) into anhydrous dirty white powder and then brown ferric oxide ($Fe_2O_3(s)$), sulphur dioxide ($SO_2(g)$), and sulphur trioxide ($SO_3(g)$).

Electrolysis of Water

The chemical decomposition of water into hydrogen gas ($H_2$) and oxygen gas ($O_2$) in a $2:1$ ratio by volume at the cathode and anode respectively, carried out by passing an electric current through acidulated water.

Photochemical Decomposition

A decomposition reaction triggered by light energy, also known as photolysis, as demonstrated by white silver chloride ($AgCl(s)$) turning grey silver in sunlight.

Displacement Reaction

A chemical reaction in which a more reactive element displaces a less reactive element from its compound solution, such as zinc displacing hydrogen from dilute hydrochloric acid.

Double Displacement Reaction

A reaction in which two compounds exchange their constituent ions to form two new compounds, such as the reaction between lead nitrate ($Pb(NO_3)_2$) and potassium iodide ($KI$).

Precipitation Reaction

A chemical reaction that produces an insoluble solid precipitate, such as the white precipitate of barium sulphate ($BaSO_4$) formed when sodium sulphate reacts with barium chloride.

Sodium Zincate

The salt with formula $Na_2ZnO_2(s)$ produced along with hydrogen gas when active zinc metal reacts with a strong base like sodium hydroxide ($NaOH$).

Neutralisation Reaction

A reaction between an acid and a base to form a salt and water, where the acid nullifies the effect of the base and vice versa.

Olfactory Indicators

Substances whose odour changes depending on whether they are in an acidic or basic medium, such as onion juice, clove oil, and dilute vanilla essence.

pH Scale

A scale used to measure hydrogen ion concentration, where values less than $7$ indicate acidic solutions, $7$ indicates neutral, and values greater than $7$ indicate basic solutions.

Water of Crystallisation

The fixed number of water molecules chemically bound inside one formula unit of a salt crystal, such as the five water molecules in hydrated copper sulphate ($CuSO_4 \cdot 5H_2O$).

Metallic Lustre

The characteristic shining or bright appearance on the clean, unoxidized surface of metals.

Malleability

The physical property of metals that allows them to be hammered or beaten into thin sheets without breaking.

Ductility

The physical property of metals that enables them to be drawn or pulled into thin wires.

Sonority

The property of metals to produce a distinct ringing sound when struck by a hard object.

Ionic Compounds

Solids formed by ionic bonding that possess high melting and boiling points, dissolve in water, and conduct electricity in the molten state or aqueous solution.

Homologous Series

A series of organic compounds sharing similar structures and chemical properties, in which consecutive members differ by a $-\text{CH}_2-$ unit and a molecular mass of $14\,\text{u}$.

Esterification

The chemical process of making an ester with a pleasant fruity smell by reacting a carboxylic acid with an alcohol in the presence of concentrated sulphuric acid.

Sodium Ethoxide

The salt ($C_2H_5O^-Na^+$) formed alongside hydrogen gas when ethanol reacts with sodium metal.

Scum

An insoluble curdy white precipitate formed when soap molecules react with hard water containing calcium and magnesium salts.

Detergents

Cleansing agents that work effectively in both soft and hard water by producing foam without forming insoluble scum.