WorksheetsIB Chemistry Topic 5 (Thermochemistry) Key Terms
Total questions: 17
Worksheet time: 10mins
What is heat?
Kinetic energy; the energy of movement
Potential energy; stored energy
Thermal energy; a form of energy that is transferred from a warmer body to a cooler body.
Mechanical energy; a form of both kinetic and potential energy
Describe an open system
the transfer of matter and energy is possible across its boundary
allows transfer of energy, but not matter
does not exchange matter or energy with its surroundings
Describe a closed system
the transfer of matter and energy is possible across its boundary
allows transfer of energy, but not matter
does not exchange matter or energy with its surroundings
Describe an isolated system
does not exchange matter or energy with its surroundings
allows transfer of energy, but not matter
the transfer of matter and energy is possible across its boundary
What is average bond enthalpy?
A measure of the average kinetic energy
Bond dissociation enthalpy
the energy required to break 1 mol of
bonds in gaseous covalent molecules under standard conditions
The energy released when one mole of a compound is burned in excess oxygen
Is bond-breaking endothermic or exothermic?
How can you find the ΔH using bond enthalpies?
Exothermic; (sum of broken bonds - sum of bonds formed)
Endothermic; (sum of products – sum of reactants)
Exothermic; (sum of products – sum of reactants)
Endothermic; (sum of broken bonds - sum of bonds formed)
What is an endothermic reaction?
A reaction in which energy is absorbed
A reaction in which energy is released
ΔH is +
ΔH is -
In which type of reaction are the products more stable than the reactants?
Endothermic
Exothermic
What is an exothermic reaction?
A reaction in which energy is evolved/released
A reaction in which energy is absorbed
ΔH is -
ΔH is +
What is enthalpy?
Average kinetic energy of a system
The total heat content of a system
Number of bonds in a system
Strength of bonds in a system
What does Hess's Law state?
Enthalpy change for a reaction depends only on difference between enthalpy of products and enthalpy of reactants.
It is independent of pathway
The energy change when one mole of a compound is formed
under standard conditions from its constituent elements in their standard states
The lattice enthalpy increases with decreasing size of the
ions and increasing charge
What is lattice enthalpy?
The energy required to vaporize one mole of a liquid
The endothermic process of converting a crystalline solid into its gaseous ions, or the reverse exothermic process
The exothermic process of converting a crystalline solid into its gaseous ions, or the reverse endothermic process
A measure of the average kinetic energy
What are standard conditions?
298K and 100atm
273K and 100kPA
298 K and 1atm
298K and 1kPA
What is temperature?
The energy released when one mole of a compound is burned in excess oxygen
The energy change when one mole of a compound is formed
under standard conditions from its constituent elements in their standard states
A measure of the average kinetic energy
The total heat content of a system
What is the standard enthalpy of vaporization?
The energy required to vaporize one mole of a liquid
A measure of the average kinetic energy
The energy released when one mole of a compound is burned in excess oxygen
The energy change when one mole of a compound is formed
under standard conditions from its constituent elements in their standard states
The energy released when one mole of a compound is burned in excess oxygen refers to:
standard enthalpy of formation
standard enthalpy of vaporization
lattice enthalpy
enthalpy of combustion
What is standard enthalpy of formation?
The energy change when one mole of a compound is formed
under standard conditions from its constituent elements in their standard states
(sum or bonds broken – sum of bonds formed)
The endothermic process of converting a crystalline solid into its gaseous ions, or the reverse exothermic process. The lattice enthalpy increases with decreasing size of the
ions and increasing charge
(sum of products – sum of reactants)
