Chemical Reactions and Equations

Comprehensive vocabulary flashcards covering key definitions, types of reactions, equation balancing, and processes from Chapter 1: Chemical Reactions and Equations.

Chemical Reaction

A process involving the breaking and making of bonds between atoms to produce new substances, indicated by observations such as a change in state, change in colour, evolution of a gas, or change in temperature.

Reactants

The starting substances that undergo chemical change in a chemical reaction, written on the left-hand side (LHS) of a chemical equation.

Products

The new substances formed during a chemical reaction, written on the right-hand side (RHS) of a chemical equation.

Burning of Magnesium Ribbon

A reaction where a cleaned magnesium ribbon burns with a dazzling white flame in the presence of oxygen to form magnesium oxide ($MgO$), a white powder.

Skeletal Chemical Equation

An unbalanced chemical equation that represents a reaction using chemical formulae, where the number of atoms of each element is not equal on both sides of the arrow.

Balanced Chemical Equation

A chemical equation in which the total number of atoms of each element is equal in both the reactants and the products, thereby satisfying the law of conservation of mass.

Hit-and-Trial Method

A method of balancing chemical equations by making trials using the smallest whole-number coefficients to equalize the number of atoms of each element on both sides.

Combination Reaction

A chemical reaction in which two or more substances (elements or compounds) combine to form a single product.

Quick Lime

The common commercial name for calcium oxide ($CaO$), an oxide that reacts vigorously with water to form slaked lime and is utilized in cement manufacturing.

Slaked Lime

The common name for calcium hydroxide ($Ca(OH)_2$), formed by the reaction of quick lime with water and used in aqueous solution for whitewashing walls.

Exothermic Chemical Reaction

A chemical reaction in which heat or energy is released along with the formation of products (e.g., the burning of natural gas and respiration).

Decomposition Reaction

A chemical reaction in which a single reactant breaks down into two or more simpler products.

Thermal Decomposition

A decomposition reaction that is driven by the application of heat energy (e.g., decomposition of $CaCO_3$ into $CaO$ and $CO_2$).

Electrolysis of Water

The decomposition of water into hydrogen and oxygen gases caused by passing an electric current through it, yielding hydrogen and oxygen in a $2:1$ volume ratio.

Endothermic Reaction

A chemical reaction in which energy is absorbed from the surroundings in the form of heat, light, or electricity.

Displacement Reaction

A chemical reaction in which a more reactive element displaces or removes another element from its compound solution (e.g., iron displacing copper from copper sulphate solution).

Double Displacement Reaction

A chemical reaction in which there is an exchange of ions between two reactants to form new compounds.

Precipitate

An insoluble solid substance formed and separated out from an aqueous solution during a chemical reaction.

Precipitation Reaction

Any chemical reaction that produces an insoluble substance or precipitate, such as the reaction between sodium sulphate and barium chloride.

Oxidation

A chemical process characterized by the gain of oxygen or the loss of hydrogen by a substance during a reaction.

Reduction

A chemical process characterized by the loss of oxygen or the gain of hydrogen by a substance during a reaction.

Redox Reaction

An oxidation-reduction reaction where one reactant gets oxidised while the other reactant gets reduced simultaneously.

Corrosion

The deterioration of a metal when it is attacked by substances around it, such as moisture and acids (e.g., rusting of iron, black coating on silver, and green coating on copper).

Rancidity

The spoilage of fat- and oil-containing foods caused by aerial oxidation, leading to an unpleasant alteration in smell and taste.

Antioxidants

Substances added to foods containing fats and oils to inhibit oxidation and prevent rancidity.