IB Chemistry Topic 4 Definitions
This page contains our IB Chemistry definitions for topic 4. By learning each one of these definitions, you will fully cover the content for IB Chemistry 'What Drives Chemical Reactions'.
anode
The electrode where electrons exit the external wire and oxidation occurs
average bond enthalpy
The energy needed to break one mole of a bond in a gaseous molecule and averaged and averaged over similar compounds
Born-Haber cycle
An energy cycle that shows the formation of ionic compounds in gas or aqueous states
calorimeter
A device that can measure an exothermic reaction's enthalpy change
cathode
The electrode where electrons enter the external wire and reduction occurs
electrolyte
A conductive solution
endothermic reaction
A reaction that absorbs heat because the reactants have stronger bonds than the products
energy
The ability to move a unit force a unit distance, measured in joules. ie the amount of work done
Energy Density
The amount of energy produced per unit mass or volume of fuel, with methanol having a higher energy density than hydrogen in fuel cells
enthalpy
The internal energy stored in molecules
enthalpy of hydration
The enthalpy change when one mole of a gaseous ionic substance is dissolved in water to form an infinitely dilute solution
enthalpy of solution
The enthalpy change when one mole of a solute is dissolved in excess solvent to form an infinitely dilute solution
entropy
The measure of distribution of available energy among particles, measured in JK-1mol-1
exothermic reaction
A reaction that releases heat because the products have stronger bonds than the reactants
heat
It is the total kinetic energy of all particles in an object
lattice enthalpy
The enthalpy change when one mole of ionic compound is broken apart into its constituent gaseous ions
specific heat capacity
The measure of how much energy a unit mass of a substance takes to be raised by 1K/1°C
spontaneity
The ease with which a reaction occurs
standard enthalpy change of combustion
Enthalpy change to completely combust one mole of a compound at STP
standard enthalpy change of formation
Enthalpy change to form one mole of a compound from its elemental constituents at STP
standard enthalpy of atomization
The enthalpy change when one mole of gaseous atoms is formed from its element at STP
standard entropy
The entropy change experienced when heating a substance from 0K to 298K (STP)
standard free energy change of a reaction
The change in free energy during a reaction, dependent on enthalpy, entropy, and temperature change
temperature
It is the average kinetic energy of an object's particles
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