Chemical Reactions and Equations - Key Vocabulary

Flashcards for vocabulary terms related to chemical reactions and equations.

Chemical Change

A change that leads to the formation of a new substance with different properties. Example: Rusting of iron, burning of paper.

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. Example: Melting of ice, boiling of water.

Chemical Reaction

A process in which substances undergo a transformation, resulting in the formation of new substances with different chemical properties. e.g., Burning of Paper/Wood or Rusting of Iron

Chemical Equation

It shows a chemical reaction using symbols and formulas to represent the reactants and products involved. Example: H2 + O2 → H₂O

Reactants

The starting materials in a chemical reaction. They are the substances that undergo a change during the reaction. In a chemical equation, reactants are typically written on the left side of the arrow.

Products

The substances that are produced as a result of the chemical reaction. They are the new substances that are formed during the reaction. In a chemical equation, products are typically written on the right side of the arrow.

Precipitate

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

Exothermic reactions

Chemical reactions that release heat energy.

Endothermic reactions

Chemical reactions in which heat energy is absorbed.

Catalyst

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

Word Equation

A qualitative way of representing a chemical reaction using the names of the reactants and products. Example: Magnesium + Oxygen → Magnesium Oxide

Skeletal Equation

An unbalanced chemical equation where the number of atoms on the reactant side are not equal to the number of atoms on the product side. Example: Mg + O2 -> MgO (unbalanced)

Balanced Chemical Equation

A chemical equation where the number of atoms of each element is the same on both sides of the equation, upholding the law of conservation of mass.

Combination Reaction

Two or more reactants combine to form one new product. A + B -> AB

Decomposition Reaction

A single compound breaks down into two or more simpler substances. AB → A + B

Displacement Reaction

A more reactive element replaces a less reactive element from its compound. A + BC → AC + B

Double Displacement Reaction

The cations and anions of two different compounds exchange places to form two new compounds. AB + CD → AD + CB

Redox Reaction

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

Oxidation

The loss of electrons or gain of oxygen or loss of hydrogen by a substance in a chemical reaction.

Reduction

The gain of electrons or loss of oxygen or gain of hydrogen by a substance in a chemical reaction.

Oxidizing Agent (Oxidant)

A substance that gives oxygen to another substance or removes hydrogen from it; it helps in the oxidation of another substance and itself gets reduced.

Reducing Agent (Reductant)

A substance that gives hydrogen to another substance or removes oxygen from it; it helps in the reduction of another substance and itself gets oxidized.

Corrosion

The attack on a metal due to chemical reactions with substances like moisture, acids, and oxygen present in the surrounding environment, leading to the destruction of the metal.

Rancidity

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