Thermodynamics

Question 1

Define standard enthalpy of atomisation

Answer 1

The enthalpy change when mole of gaseous atoms is formed from the element in its standard state under standard conditions

Question 2

Define first electron affinity

Answer 2

The standard enthalpy change when one mole of gaseous atoms is converted into one mole of gaseous ions, each with a single negative charge

Question 3

Define second electron affinity

Answer 3

The enthalpy change when mole of electrons is added to one mole of gaseous ions, each with a single negative charge to form one mole of gaseous ions each with 2 negative charges

Question 4

Define first ionisation energy

Answer 4

The standard enthalpy change when one mole of gaseous atoms is converted into one mole of gaseous ions each carrying a single positive charge

Question 5

Is first ionisation energy an endo- or exothermic reaction?

Answer 5

Endothermic

Question 6

Is first electron affinity an endo- or exothermic reaction?

Answer 6

Exothermic

Question 7

Is second electron affinity an endo- or exothermic reaction?

Answer 7

Endothermic

Question 8

Why is second electron affinity endothermic?

Answer 8

Involves bringing together 2 negative charges - naturally these want to repel