Chemistry Definitions – Chemical Calculations, Bonding, and Energy

A set of vocabulary flashcards covering key chemical terms related to calculations, bonding, and energy changes.

Molar Mass

The mass in grams of one mole of a substance.

Solution

A homogeneous mixture of solute and solvent.

Solute

The substance that is dissolved in a solution.

Solvent

The substance in which another substance is dissolved, forming a solution.

Standard Solution

A solution whose concentration is precisely known.

Yield

A measure of the extent of a reaction, often expressed as the amount of product obtained compared to the theoretical amount possible.

Molar Concentration

The amount of solute per unit volume of solution (typically mol · L⁻¹).

Electronegativity

A measure of an atom’s tendency to attract a bonding pair of electrons.

Intramolecular Bond

A bond that occurs between atoms within a molecule.

Covalent Bond

A bond formed by the sharing of at least one pair of electrons between two atoms.

Non-polar Covalent Bond (Pure Covalent)

A covalent bond in which electrons are shared equally between atoms.

Polar Covalent Bond

A covalent bond with unequal electron sharing, resulting in a dipole due to electronegativity differences.

Ionic Bond

A bond formed by the transfer of electrons and the electrostatic attraction between resulting ions.

Metallic Bond

The attraction between positive metal kernels and a sea of delocalised electrons.

Intermolecular Force

A weak force of attraction between molecules or between atoms of noble gases.

Heat of Reaction (ΔH)

The net change in chemical potential energy of a system during a reaction.

Exothermic Reaction (ΔH < 0)

A reaction that converts chemical potential energy into thermal energy, releasing heat.

Endothermic Reaction (ΔH > 0)

A reaction that absorbs heat, converting thermal energy into chemical potential energy.

Activation Energy

The minimum energy required to start a reaction or to form the activated complex.

Activated Complex

A short-lived, high-energy, unstable transition state between reactants and products.

Reaction Rate

The change in amount or concentration of a reactant or product per unit time.

Catalyst

A substance that increases the reaction rate without being permanently consumed.