Thermodynamics (definitions)

Question 1

Enthalpy of formation

Answer 1

Enthalpy change when one mole of substance is formed from its constituent elements under standard states and standard conditions.

Question 2

Enthalpy of combustion

Answer 2

Enthalpy change when one mole of substance is completely burned in oxygen under standard states and conditions.

Question 3

Enthalpy of atomisation

Answer 3

Enthalpy change which accompanies the formation of one mole of gaseous atoms from the element in its standard states and standard conditions.

Question 4

First ionisation energy

Answer 4

Standard enthalpy change when one mole of gaseous atoms is converted to a mole of gaseous ions each with a single positive charge.

Question 5

Second ionisation energy

Answer 5

refers to the loss of a mole of electrons from a mole of singly