3.2.1 Notes And Definitions

Question 1

What is the equation for enthalpy change?

Answer 1

Products - Reactants

Question 2

Which direction does heat travel for exo/endo?

Answer 2

Exo: FROM System TO Surroundings
Endo: from Surroundings TO System

Question 3

Define activation energy

Answer 3

The minimum amount of energy required for a reaction to take place

Question 4

Standard conditions and units

Answer 4

Pressure: 100kPa
Temp: 298K

Units are kJmol

Question 5

Define the standard enthalpy change of reaction

Answer 5

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 the standard states

Question 6

Define the standard enthalpy change of formation

Answer 6

The enthalpy change that takes place when one mole of a compound is formed from its elements under standard conditions with standard states

Question 7

Define the standard enthalpy change of combustion

Answer 7

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 states

Question 8

Define the standard enthalpy change of neutralisation

Answer 8

The end of a change that accompanies the reaction of an acid and a base to form one mole of water under standard conditions with standard states

Question 9

How to calculate energy changes

Answer 9

E=mc(delta)t
n= cv, or n = mass/mr

Divide E by N to get ans

Question 10

Define average bond enthalpy

Answer 10

Energy required to break 1 mol of a type of bond in a gaseous molecule
They are ALWAYS Endothermic

Question 11

What ways do the arrows go for combustion when making a Hess cycle

Answer 11

Down

Question 12

What ways do the arrows go for formation when making a Hess cycle

Answer 12

Up