Chemistry Definitions Grade 11

Molar Mass

The mass in grams of one mole of that substance

Molar concentration

The amount of solute per unit volume of solution

Electronegativity

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

Heat of Reaction

The net change of chemical potential energy of the system

Exothermic Reaction

Reactions which transform chemical potential energy into thermal energy

Endothermic reaction

Reactions which transform thermal energy into chemical potential energy

Activation Energy

The minimum energy required to start a chemical reaction

OR

The energy required to form the activated complex

Reaction Rate

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

Catalyst

A substance that increases the rate of the reaction but remains unchanged at the end of the reaction

Hydrocarbon

A compound containing only carbon and hydrogen atoms

Saturated Compound

A compound in which all of the bonds between carbon atoms are single bonds

Unsaturated Compound

A compound in which there is at least one double and/or triple bond between carbon atoms

Functional Group

An atom or a group of atoms that form the centre of chemical activity in the molecule

Homologous Series

a series of similar compounds which have the same functional group and have the same general formula, in which each member differs from the previous one by a single CH2 unit

Structural Isomers

Compounds having the same molecular formula but different structural formulae