Module 3

Question 1

Define activation energy.

Answer 1

The minimum energy required to start a reaction by the breaking of bonds

Question 2

Define average bond enthalpy.

Answer 2

Average enthalpy change when one mole of bonds of gaseous covalent bonds is broken

Question 3

Define enthalpy change of formation.

Answer 3

The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in there standard states under standard conditions of 298K and 1 atm

Question 4

Define enthalpy change of combustion.

Answer 4

The enthalpy change that takes place when one mole of a substance completely combusts under standard conditions and states of 298K and 1 atm

Question 5

Define periodicity.

Answer 5

Repeating trends in properties of the elements across each period of the periodic table

Question 6

Define 1st ionisation energy.

Answer 6

The energy required to remove one electron from each atom in one mole of gaseous atoms of an element

Question 7

Define 2nd ionisation energy.

Answer 7

The energy required to remove one electron from each ion in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions