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Flashcards in Physical Deck (18):
1

Enthalpy change definition

Heat energy transferred in a reaction at constant pressure (kilojoules per mole)

2

Standard enthalpy of formation definition

The enthalpy change when one mole of a compound is formed from its elements in their standard states under standard conditions

3

Standard enthalpy of combustion definition

Enthalpy change when one mole of a substance is completely burned in oxygen under standard conditions

4

Calorimetry equation

q=mct(change)

5

Hess’s law

The total enthalpy of reaction is independent of route taken

6

What is activation energy

The minimum amount of kinetic energy that particles need to react

7

Le Chateliers principal

If a reaction at equilibrium is subjected to a change in concentration pressure or temperature the position of equilibrium will move to counteract the change

8

Effect of temperature catalysts and concentration on Kc

If temperature change means more product at equilibria Kc will rise
Catalysts no change
Concentration no change

9

Enthalpy change of atomisation of an element

Enthalpy change When one mole of gaseous atoms is formed from an element in its standard state

10

First electron Affinity

Enthalpy change when one mole of gaseous 1- ions is formed from 1 mole of gaseous atoms

11

Enthalpy change of hydration

Enthalpy change when one mole of aqueous ions is formed from one mole of gaseous ions

12

Enthalpy change of solution

Enthalpy Change when one mole of solute is dissolved in enough solvent that no further enthalpy change occurs on further dilution

13

Lattice enthalpy of formation definition

Enthalpy change when one mole of a solid ionic compound is formed from its gaseous ions under standard conditions

14

Lattice enthalpy of dissociation definition

Enthalpy change when one mole of a solid ionic compound is completely dissociated into its gaseous ions under standard conditions

15

Entropy change equation

Entropy change= entropy of products-entropy of reactants

16

How to know whether a reaction is feasible using free energy change

Free energy change must be negative or equal to 0

17

Gibbs free energy change equation

Free energy change= enthalpy change - (temperature x entropy change)

18

Mole fraction equation

Mole fraction = number of moles of gas/total number of moles of gas in the mixture