Bond Enthalpy

Question 1

What is the definition of Endothermic reaction?

Answer 1

Reaction in which energy enters the surroundings

Question 2

What is the definition of Exothermic reaction?

Answer 2

Reaction in which energy leaves the system to surroundings

Question 3

Examples of Exothermic.

Answer 3

Combustion, neutralisation reaction

Question 4

Examples of Endothermic.

Answer 4

Thermal decomposition, photosynthesis

Question 5

What is enthalpy change equation?

Answer 5

Enthalpy of products - Enthalpy of reactants

Question 6

Draw the reaction profile of Exothermic.

Answer 6

-Products lower than reactants
-AE is from reactants upwards.
-Energy released is from reactants to products

Question 7

Draw the reaction profile of Endothermic.

Answer 7

-Products are higher than reactants
-AE from reactants to peak
-Energy absorbed is from products to reactants

Question 8

What is the definition of enthalpy change of combustion?

Answer 8

Enthalpy change for the complete combustion of 1 mole of a substance

Question 9

What is defintion
enthalpy change of formation?

Answer 9

Enthalpy change where one mole of a compound is formed from its elements in their standard states

Question 10

What does Hess’s law state?

Answer 10

The total enthalpy change for a reaction is the same whichever route is taken

Question 11

For combustion, what way are the arrows pointing?

Answer 11

Away from reactants towards products

Question 12

For Formation, what way are the arrows pointing?

Answer 12

Towards the reactants and towards the products

Question 13

What is the equation for enthalpy of oxidation?

Answer 13

ΔH1= ΔH2+ ΔH3

Question 14

What the equation for enthalpy of formation?

Answer 14

ΔHr= -(ΔH1)+( ΔH2)