definitions

Question 1

enthalpy change

Answer 1

• the heat energy
• transferred in a reaction
• at a constant pressure

Question 2

enthalpy change of formation

Answer 2

• the enthalpy change when
• 1 mole of a compound is formed
• from its elements in their standard states
• under standard conditions

Question 3

bond dissociation enthalpy

Answer 3

• the enthalpy change when all the bonds of the same type
• in one mole of gaseous molecules
• are broken

Question 4

enthalpy change of atomisation of an element

Answer 4

• the enthalpy change when 1 mole
• of gaseous atoms
• is formed from an element
• in its standard state

Question 5

enthalpy change of atomisation of a compound

Answer 5

• the enthalpy change when 1 mole
• of a compound
• in its standard state
• is converted to gaseous atoms

Question 6

first ionisation energy

Answer 6

• the enthalpy change when 1 mole
• of gaseous 1+ ions
• is formed from 1 mole of gaseous atoms

Question 7

second ionisation energy

Answer 7

• the enthalpy change when one mole
• of gaseous 2+ ions is formed
• from 1 mole
• of gaseous 1+ ions

Question 8

first electron affintity

Answer 8

• the enthalpy change when 1 mole
• of gaseous 1- ions is formed
• from 1 mole of gaseous atoms

Question 9

second election affitnty

Answer 9

• the enthalpy change when 1 mole
• of gaseous 2- ions is formed
• from 1 mole of gaseous 1- ions

Question 10

enthalpy change of hydration

Answer 10

• the enthalpy change when 1 mole
• of aqueous ions is formed
• from 1 mole of gaseous ions

Question 11

enthalpy change of solution

Answer 11

• the enthalpy change when 1 mole of solute is dissolved
• in enough solvent
• so that no further enthalpy change occurs
• on further dilution

Question 12

lattice enthalpy of formation

Answer 12

• the enthalpy change when 1 mole
• of a solid ionic compound is formed
• from its gaseous ions
• under standard condtitions

Question 13

colour of VO2 (+)

Answer 13

yellow

Question 14

colour of VO (2+)

Answer 14

blue

Question 15

colour of V (3+)

Answer 15

green

Question 16

colour of V (2+)

Answer 16

violet

Question 17

colour of Cr2O7 (2-)

Answer 17

orange

Question 18

colour of Cr (3+)

Answer 18

violet / green
- violet when surrounded by 6 water ligands
- but when substituted they appear green

Question 19

colour of MnO4 (-)

Answer 19

purple

Question 20

colour of Mn (2+)

Answer 20

pale pink

Question 21

colour of Fe (3+)

Answer 21

• purple / yellow
• when surrounded by water ligands, appears purple
• but often undergoes hydrolysis and appear yellow

Question 22

colour of Fe (2+)

Answer 22

pale green

Question 23

colour of Co (2+)

Answer 23

pink

Question 24

colour of Ni (2+)

Answer 24

green

Question 25

colour of Cu (2+)

Answer 25

blue