Periodic Table And Energy

Question 1

Define periodicity

Answer 1

Repeating trend in properties of the elements across each period

Question 2

Define atomic radius

Answer 2

Half the internuclear distance in the metallic lattice or for none metallic elements the half covelant radius

Question 3

Define ionisation energy

Answer 3

A measure of how easily an atom loses electrons to Positive ions

Question 4

Define the first ionisation energy

Answer 4

Energy required to remove one electron from each atom in a mole of atoms in gaseous form

Question 5

How is -ClO made

Answer 5

Cl2 + H20 —> HCl + HClO

Cl2 + NaOH —> HCl + NaClO

Question 6

*What are the standard enthalpy conditions?

Answer 6

100kpa
298kelvin
1.0 moldm-3

Question 7

*Standard enthalpy reaction definition

Answer 7

The enthalpy change that accompanies a reaction in the molar quantities shown in a chemical equation under standard conditions with all reactants and products in their standard state

Question 8

*Standard enthalpy of formation Definition

Answer 8

Enthalpy change that takes place when a mole of a compound is formed from its elements under standard conditions with all reactants and products in standard their state

Question 9

*Standard enthalpy for combustion definition

Answer 9

Enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions with all reactants and products in their standard state

Question 10

What is hess’ law

Answer 10

Overall energy change for a reaction is independent of the route taken

Question 11

*Define the enthalpy change of neutralisation

Answer 11

The enthalpy change that occurs when one mole of water is formed by the reaction of an acid with a base under standard conditions with all reactants and products in their standard states