Year 10 Energy changes

1

Identify the type of change for the reaction: NaCl(s) + H₂O(l) → NaCl(aq)

a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

1

Identify the type of change for the reaction: NaOH + HCl → NaCl + H₂O

a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

1

Identify the type of change for the following reaction: Cl₂ + 2NaBr → 2NaCl + Br₂

a salts dissolving in water

b neutralisation reactions

c displacement reactions

d precipitation reactions

1

Identify the type of change for the following reaction: Fe + CuSO₄ → FeSO₄ + Cu
a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

1

Identify the type of change for the reaction: AgNO₃(aq) + NaCl(aq) → NaNO₃(aq) + AgCl(s)

Hint - look at the state symbols

1

In an exothermic reaction, heat energy is:_________________ to the surroundings.

1

In an endothermic reaction, heat energy is:________________________ from the surroundings.

1

Bond breaking is:

1

Bond forming is:

1

In an exothermic reaction:

1

In an endothermic reaction:

1

What is the minimum energy needed to break the bonds in the reactants is called _______________energy.

Other Answer Choices:

activation

4

Combustion of methane
This is a reaction profile diagram for an _______________  reaction. (1 Point)
Energy needed to break the bonds in the ______________(the  _______________energy) 
is less than the energy released when the bonds form in the _____________. 
Copy this diagram and explanation into your exercise books.

Other Answer Choices:

reactants

products

exothermic

endothermic

activation

1

Respiration
This is a reaction profile diagram for an _______________  reaction. (1 Point)
Energy needed to break the bonds in the ______________(the  _______________energy) 
is less than the energy released when the bonds form in the _____________. 

Other Answer Choices:

exothermic

endothermic

products

activation

reactants

1

Which letter represents the activation energy? A, B, or C? (1 Point)

1

Which letter represents the overall energy change? (1 Point)

1

Which letter represents the energy change for breaking bonds? A, B, or C? (1 Point)

1

Which letter represents the energy change for making bonds?
Note the arrow should be going downwards but this was a multiple choice question.

1

The energy change is endothermic or exothermic. (1 Point)

1

In this change, would the surroundings get hotter or cooler?
exothermic

1

In this change, the temperature of the surroundings would (1 Point) increase or decrease?

1

Calculate the energy change. 

Total energy taken in to break bonds in the reactants

 = 4 x C-H + 2 x O=O
= 4 x 414 + 2 x 498 = 2652_______ kJ / mol
Total energy given out when bonds form in products

= 2x C=O + 4 x O-H
= 2 x 803 + 4 x 464
= _______ kJ/mol
Energy change = energy to break bonds - energy to make bonds
= 2652 - 3462 = sign _______ value _______ kJ/mol.
Note this is an _______ reaction so energy is released to the surroundings and the temperature of the surroundings _______ 

1

This reaction profile shows an ________________  reaction.
Activation energy  = ______
Energy needed to break bonds in reactants =  ______ 
Energy released when new bonds form in the products = ______ 
Energy change in the reaction = ______ 
Energy in to break bonds is less than energy released to make bonds so the reaction is ________________.
The reaction takes in energy so the surrounding will lose energy and the temperature will _____________  

Other Answer Choices:

A

exothermic

decrease

endothermic

B

increase

1

Which letter represents the activation energy?

1

Which letter represents the energy needed to break the bonds in the reactants? A, B, or C? (1 Point)

1

Which letter represents the energy needed to form the bonds in the products? (1 Point)

1

Which letter represents the energy change for the reaction? (1 Point)

1

The temperature of the surroundings will:

1

Please choose the correct statement.

6

Energy needed to break the bonds in the reactants
= 1 x N=N + 1 x O=O
= 945 + 498
= _______ kJ/mol
Energy given out when bonds form in the products
= 2 x N=O
= 2x 630
= _______ kJ/mol
Energy change = energy needed to break bonds - energy released when bonds form
= 1413 - 1260
= sign _______ value _______  
The energy change is positive so the reaction is _______ and the temperature of the surroundings will _______ 

1

Draggable item		Corresponding Item
Energy change value		4 x C-H + Cl-Cl
Energy to make bonds		= 4 x 413 + 243
Energy to break bonds		= 1895 kJ / mol
Sum of energy to break bonds		3 x C-H + 1 x C-Cl + H-Cl
Bond broken =		= 3 x 413 + 327 + 432
Sum of energy to make bonds		= 1998
Reaction is		= bonds broken - bonds made
Energy change formula		1895 - 1998
Energy change calculation		-103 kJ/mol
Bonds made =		exothermic

Year 10 Energy changes

Identify the type of change for the reaction: NaCl(s) + H₂O(l) → NaCl(aq)a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: NaOH + HCl → NaCl + H₂Oa salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the following reaction: Cl₂ + 2NaBr → 2NaCl + Br₂a salts dissolving in waterb neutralisation reactionsc displacement reactions d precipitation reactions

Identify the type of change for the following reaction: Fe + CuSO₄ → FeSO₄ + Cua salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: AgNO₃(aq) + NaCl(aq) → NaNO₃(aq) + AgCl(s)Hint - look at the state symbols

In an exothermic reaction, heat energy is:_________________ to the surroundings.

In an endothermic reaction, heat energy is:________________________ from the surroundings.

Bond breaking is:

Bond forming is:

In an exothermic reaction:

In an endothermic reaction:

Combustion of methane

Respiration

Which letter represents the activation energy? A, B, or C? (1 Point)

Which letter represents the overall energy change? (1 Point)

Which letter represents the energy change for breaking bonds? A, B, or C? (1 Point)

Which letter represents the energy change for making bonds? Note the arrow should be going downwards but this was a multiple choice question.

The energy change is endothermic or exothermic. (1 Point)

In this change, would the surroundings get hotter or cooler?exothermic

In this change, the temperature of the surroundings would (1 Point) increase or decrease?

Which letter represents the activation energy?

Which letter represents the energy needed to break the bonds in the reactants? A, B, or C? (1 Point)

Which letter represents the energy needed to form the bonds in the products? (1 Point)

Which letter represents the energy change for the reaction? (1 Point)

The temperature of the surroundings will:

Please choose the correct statement.

Identify the type of change for the reaction: NaCl(s) + H₂O(l) → NaCl(aq)a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: NaOH + HCl → NaCl + H₂Oa salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the following reaction: Cl₂ + 2NaBr → 2NaCl + Br₂a salts dissolving in waterb neutralisation reactionsc displacement reactions d precipitation reactions

Identify the type of change for the following reaction: Fe + CuSO₄ → FeSO₄ + Cua salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: AgNO₃(aq) + NaCl(aq) → NaNO₃(aq) + AgCl(s)Hint - look at the state symbols

In an exothermic reaction, heat energy is:_________________ to the surroundings.

In an endothermic reaction, heat energy is:________________________ from the surroundings.

Bond breaking is:

Bond forming is:

In an exothermic reaction:

In an endothermic reaction:

Combustion of methane

Respiration

Which letter represents the activation energy? A, B, or C? (1 Point)

Which letter represents the overall energy change? (1 Point)

Which letter represents the energy change for breaking bonds? A, B, or C? (1 Point)

Which letter represents the energy change for making bonds? Note the arrow should be going downwards but this was a multiple choice question.

The energy change is endothermic or exothermic. (1 Point)

In this change, would the surroundings get hotter or cooler?exothermic

In this change, the temperature of the surroundings would (1 Point) increase or decrease?

Which letter represents the activation energy?

Which letter represents the energy needed to break the bonds in the reactants? A, B, or C? (1 Point)

Which letter represents the energy needed to form the bonds in the products? (1 Point)

Which letter represents the energy change for the reaction? (1 Point)

The temperature of the surroundings will:

Please choose the correct statement.

Identify the type of change for the reaction: NaCl(s) + H₂O(l) → NaCl(aq)

a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: NaOH + HCl → NaCl + H₂O

a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the following reaction: Cl₂ + 2NaBr → 2NaCl + Br₂

a salts dissolving in water

b neutralisation reactions

c displacement reactions

d precipitation reactions

Identify the type of change for the following reaction: Fe + CuSO₄ → FeSO₄ + Cu
a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: AgNO₃(aq) + NaCl(aq) → NaNO₃(aq) + AgCl(s)

Hint - look at the state symbols

Which letter represents the energy change for making bonds?
Note the arrow should be going downwards but this was a multiple choice question.

In this change, would the surroundings get hotter or cooler?
exothermic

Identify the type of change for the reaction: NaCl(s) + H₂O(l) → NaCl(aq)

a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: NaOH + HCl → NaCl + H₂O

a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the following reaction: Cl₂ + 2NaBr → 2NaCl + Br₂

a salts dissolving in water

b neutralisation reactions

c displacement reactions

d precipitation reactions

Identify the type of change for the following reaction: Fe + CuSO₄ → FeSO₄ + Cu
a salts dissolving in water b neutralisation reactions c displacement reactions d precipitation reactions

Identify the type of change for the reaction: AgNO₃(aq) + NaCl(aq) → NaNO₃(aq) + AgCl(s)

Hint - look at the state symbols

Which letter represents the energy change for making bonds?
Note the arrow should be going downwards but this was a multiple choice question.

In this change, would the surroundings get hotter or cooler?
exothermic