Module 5 - Definitions

Question 1

Enthalpy of Atomisation

Answer 1

The enthalpy change when 1 mole of gaesous atoms is from an element in its standard state

Question 2

Enthalpy of Solution

Answer 2

Enthalpy change when one mole of an ionic solid dissolves completely in enough water to form its consistuent ions.

Question 3

First Electron Affinity

Answer 3

The enthalpy change when one mole of gaseous ions gain one mole of electrons to form 1 mole of gaseous 1- ions.

Question 4

Lattice Enthalpy

Answer 4

The standard enthalpy change when one mole of an ionic crystal lattice is formed from its consistuent ions in gaseous from.

Question 5

Enthalpy of Hydration

Answer 5

Enthalpy change when 1 mole of gaseous ions become aqeuous ions.

Question 6

Standard electrode potential?

Answer 6

The p.d measured when an electrode system is connected to the hydrogen electrode system , and standard conditions apply.

Question 7

What is a buffer solution?

Answer 7

pH does not change significantly if small amounts of acid or alkali are added to it.

Question 8

What are the components of a acidic buffer solution?

Answer 8

A weak acid and and a salt of that weak acid.

Question 9

What are the components of a basic buffer solution?

Answer 9

A weak base and a salt of that weak base.

Question 10

What attractions do negative ions form with water?

Answer 10

Ion-dipole attractions between the negative ions and the s+ hydrogen atoms in water molecules.

Question 11

2 factors that affect the enthalpy of hydration.

Answer 11

• atomic radius of ion

- charge of ion