Energetics

Question 1

Standard enthalpy of formation

Answer 1

Enthalpy change when 1 mol of a substance at standard conditions is formed by its component elements at standard state

Question 2

Standard enthalpy change of combustion

Answer 2

Enthalpy change when 1 mole of element/compound in standard state undergoes complete combustion with excess oxygen to form products in standard state

Question 3

Standard enthalpy change of neutralization

Answer 3

Enthalpy change when 1 mole of aqueous solution of H+ ions and 1 mol of aqueous OH- ion in standard state react to form 1 mol of liquid water at standard state

Question 4

Standard enthalpy change of bond dissociation

Answer 4

Enthalpy change when a gaseous compound in standard state undergoes dissociation in the standard state by breaking 1 mol of bonds

Question 5

Standard enthalpy change of solvation

Answer 5

Enthalpy change when 1 mol of gaseous ions in standard state changes into a solution with 1moldm-3 concentration

Question 6

Standard enthalpy change of hydration

Answer 6

Enthalpy change when 1 mol of gaseous ions in the standard state changes into a solution with water with 1 moldm-3 concentration

Question 7

Standard enthalpy change of dissolution

Answer 7

Enthalpy changes when 1 mol of a substance at standard state dissolves in a solvent (usually water) to form a solution with 1moldm-3 concentration

Question 8

Standard enthalpy change of sublimation

Answer 8

Enthalpy change when 1 mol of solid element/compound in standard state converts completely into a gas at standard state

Question 9

Standard enthalpy change of vapourization

Answer 9

Enthalpy change of 1 mol of liquid element/compound converts into 1 mol of gaseous compound or element at standard state

Question 10

Standard engthalpy change of fusion

Answer 10

Enthalpy change when 1 mol of solid/element or compound in standard state converts to 1mol of liquid compound/element at standard state

Question 11

Standard enthalpy change of atomization

Answer 11

Enthalpy change when an element of standard state is converted to a mol of gaseous atoms at standard state

Question 12

Standard enthalpy change of 1st ionization

Answer 12

Enthalpy change when removing 1 mol of gaseous atoms at standard state to form 1 mol of singly charged positive gaseous ions at standard state

Question 13

Standard enthalpy change of 2nd ionization

Answer 13

Enthalpy change when removing 1 mol of most loosly bound electrons from a singly charged postive gaseous ions at standard state to form doubly charged gaseous ion at standard state

Question 14

Standard enthalpy change of 1st electron gain

Answer 14

Enthalpy change when 1 mol of a singly charged gaseous ion at standard state are formed by gaining electrons to 1 mol of gaseous atoms at standard state

Question 15

Standard lattice dissociation enthalpy change

Answer 15

Enthalpy change when 1 mol of a solid, ionic compound is converted to its gaseous ions at standard state

Question 16

Standard lattice enthalpy change

Answer 16

Enthalpy change when 1 mol of solid ionic compounds in standard state is formed from its gaseous positive ions and gaseous negative ions at gas state