Changes of Matter and Chemical Reactions Flashcards

These flashcards cover vocabulary related to physical and chemical changes, specific types of chemical reactions, the properties of acids, and concepts of oxidation, reduction, corrosion, and food preservation.

Physical change

A change in which the identity of the substance remains the same and only its physical properties (such as shape, size, or state) are altered, for example, the melting of ice.

Chemical change

A change that leads to the formation of a new substance with different properties, such as the rusting of iron.

Aqueous solution

A solution in which water is the solvent, which is the substance that dissolves another substance.

Chemical Reaction

A process in which substances undergo a transformation resulting in the formation of new substances with different chemical properties.

Chemical Equation

A representation of a chemical reaction using symbols and formulas to show the reactants and products involved.

Endothermic Reaction

A chemical reaction in which heat energy is absorbed from the surroundings.

Exothermic Reaction

A chemical reaction that releases heat energy into the surroundings.

Reactive metal

A metal that easily donates electrons during a chemical reaction.

Reactive non-metal

A non-metal that easily accepts electrons during a chemical reaction.

Precipitate

An insoluble solid that settles down after the completion of a chemical reaction.

Catalyst

A substance that speeds up a chemical reaction or lowers the temperature or pressure needed to start one without being consumed during the reaction.

Law of conservation of mass

A law stating that in a chemical reaction, mass is neither created nor destroyed, meaning the mass of the reactants is equal to the mass of the products.

King of acids

Sulphuric acid ($H_2SO_4$).

Queen of acids

Nitric acid ($HNO_3$).

Combination (Synthesis) reaction

A chemical reaction where two or more substances combine to form a single new substance, represented as $A + B \rightarrow AB$.

Decomposition Reaction

A type of chemical reaction where a single compound breaks down into two or more simpler substances, usually caused by heat, light, or electricity.

Thermolysis

Also known as thermal decomposition, it is a reaction where a compound breaks down into simpler substances when heated.

Electrolytic Decomposition

A reaction where an electric current is used to decompose or break down compounds into their constituent elements or ions.

Photolytic Decomposition

Decomposition reactions that are initiated by exposure to light or sunlight.

Displacement reaction

A chemical reaction in which a more reactive element replaces a less reactive element from its compound, represented as $A + BC \rightarrow AC + B$.

Double Displacement reaction

A chemical reaction in which the cations and anions of two different compounds exchange places to form two new compounds, represented as $AB + CD \rightarrow AD + CB$.

Precipitate (Ppt) Reaction

A reaction in which two aqueous ionic solutions react to form an insoluble solid that separates from the solution.

Oxidation

The addition of oxygen, the removal of hydrogen, the loss of electrons, or the addition of an electronegative element to a substance.

Oxidizing agent

A substance that causes oxidation by accepting electrons, thereby becoming reduced itself.

Reduction

A chemical reaction involving the addition of hydrogen, the removal of oxygen, or the removal of an electronegative element.

Reducing agent

A substance that brings about reduction and is itself oxidized during the reaction.

Redox Reaction

A chemical reaction in which reduction and oxidation take place simultaneously.

Corrosion

The attack on a metal due to chemical reactions with substances like moisture, acids, and the environment, leading to damage or weakening of materials.

Rancidity

The condition produced by the oxidation of fats and oils in food material, resulting in a bad taste and unpleasant smell.

Rusting

The oxidation process where iron reacts with air and water to form a reddish-brown flaky substance on its surface.

Tarnishing

A process where silver reacts with hydrogen sulfide and oxygen in the air to form compounds that darken the silver surface.

Antioxidants

Chemical substances added to food containing fats and oils to inhibit oxidation and prevent spoiling.

Dilute solution

A solution with a low amount of solute, resulting in weak strength.

Concentrated solution

A solution with a high amount of solute, resulting in strong strength.

Electrolyte

A substance that allows an electric current to pass through it.