Topic 8 - Energetics 1

Question 1

Enthalpy change

Answer 1

Heat energy change at constant pressure

Question 2

Standard conditions

Answer 2

100 kPa, 298K, 1 moldm^-3

Question 3

Exothermic

Answer 3

-ve enthalpy change

Question 4

Endothermic

Answer 4

+ve enthalpy change

Question 5

Standard enthalpy change of reaction (ΔHr°)

Answer 5

Enthalpy change when reaction occurs in the molar quantities shown under standard conditions

Question 6

Standard enthalpy change of formation (ΔHf°)

Answer 6

Enthalpy change when one mole of a compound is formed from its elements in their standard states under standard conditions

Question 7

Enthalpy change of combustion (ΔHc°)

Answer 7

Enthalpy change when one mole of a substance is completely burned in oxygen under standard conditions

Question 8

Enthalpy change of neutralisation (ΔHneut°)

Answer 8

Enthalpy change when an acid and alkali react together under standard conditions to form one mole of water

Question 9

Specific heat capacity

Answer 9

The amount of energy needed to raise the temperature of 1 gram of a substance by 1°C

Question 10

Hess’ Law

Answer 10

The total enthalpy change of the reaction is independent of the path taken

Question 11

Bond enthalpy

Answer 11

Amount of energy required to break one mole of the stated bond in a gaseous state