Chapter 17: Thermodynamics

Question 1

Define the standard enthalpy of formation

Answer 1

The enthalpy change when one mole of compound is formed from its consituent elements under standard conditions, all reactants and products in their standard states.

Question 2

Define the first electron affinity

Answer 2

The standard enthalpy change when one mole of gaseous atoms is converted into one mole of gaseous ions all with a single positive charge.

Question 3

Define the standard enthalpy of combustion,

Answer 3

The enthalpy change when one mole of a substance is burned completely in oxygen.

Question 4

Define the lattice enthalpy of formation

Answer 4

The standard enthalpy change when a solid ionic compund is formed from it’s gaseous ions.

Question 5

Enthalpy of hydration

Answer 5

is the standard enthalpy change when water molecules surround one mole [of gaseous ions.

Question 6

Mean bond enthalpy

Answer 6

The enthalpy change when one mole of gaseous molecules each breaks a covalent bond to form two free radicals, averaged over a range of compounds.

Question 8

Draw a Hess cycle