WorksheetsC7- Energy Changes
Total questions: 30
Worksheet time: 15mins
C7.1- Which of these correctly describes an exothermic reaction?
A reaction that takes energy from the surroundings
A reaction that releases heat into the surroundings
A reaction that does not affect its surroundings
A reaction done in a polystyrene cup
C7.1- Which of these correctly describes an endothermic reaction?
A reaction that takes energy from the surroundings
A reaction that releases heat into the surroundings
A reaction that does not affect its surroundings
A reaction done in a polystyrene cup
C7.1- How can you tell a reaction is endothermic?
Because the colour changes
Because the reaction effervesces
Because the temperature of the solution increases
Because the temperature of the solution decreases
C7.1- How can you tell a reaction is exothermic?
Because the colour changes
Because the reaction effervesces
Because the temperature of the solution increases
Because the temperature of the solution decreases
C7.1- Which of these is NOT a measurement that needs to be made when investigating the energy change of a reaction?
Starting temperature
Final temperature
Mass of reactants
Temperature of surroundings
C7.1- Why do we measure energy changes of endothermic reactions in polystyrene cups?
To minimise energy loss to the surroundings
To minimise energy gain from the surroundings
To make sure the reaction releases all of its energy
To stop air getting in
C7.2- Which of these is NOT an exothermic reaction?
Self-heating can
Hand warmer
Combustion
Photosynthesis
C7.2- Which of these is NOT an endothermic reaction?
Photosynthesis
Sports injury pack
Dissolving ammonium chloride
Respiration
C7.2- Which letter represents the endpoint of the titration in the graph?
A
B
C
D
C7.2- Why is the temperature increasing at point A?
Energy is gained from the surroundings
The reaction is exothermic
The reaction is endothermic
There is a bunsen burner being used
C7.2- Why is the temperature decreasing at point C?
Energy is lost the surroundings
The reaction is exothermic
The reaction is endothermic
There is an ice bath being used
C7.3- What type of reaction is shown by the energy profile diagram?
Exothermic
Endothermic
Both
Neither
C7.3- What type of reaction is shown by the energy profile diagram?
Exothermic
Endothermic
Both
Neither
C7.3- What does the red arrow represent in the diagram?
Activation energy
Energy lost to surroundings
Energy gained from surroundings
Temperature increase
C7.3- Why does the energy in the chemical increase initially?
Because energy is needed to make bonds
Because energy is needed to break bonds
Because it is getting hotter
Because it is storing energy for later
C7.3- Why does the energy in the chemical decrease at the end?
Because energy is released when bonds are made
Because energy is released when bonds break
Because it is getting colder
Because it is releasing energy stored earlier
C7.3- What does Ea mean in the diagrams?
Energy applied
Energy added
Activation Energy
Actual Energy
C7.4- Bond breaking is...
Easy
Exothermic
Endothermic
Impossible
C7.4- Bond making is...
Impossible
Exothermic
Endothermic
Easy
C7.4- How many C=O bonds are made when forming 4CO2?
1
2
4
8
C7.4- If your bond enthalpy diagram gives a negative number, this means it is...
Wrong
Exothermic
Endothermic
Correct
C7.4- What is the energy changes associated with the following reaction?
+183
-183
813
-813
C7.5- What is the missing chemical shown by "?" ?
Tap water
Acid
Salt solution
Distilled water
C7.5- What type of chemical battery produces the biggest potential difference?
The one with the most reactive metal
The one with the least reactive metal
The one with all the metals the same
The one with the biggest difference between reactivity of the metals
C7.5- How do rechargeable batteries work?
They contain four types of metal
The reaction within them is reversible
They can store electricity
The chemicals can be easily topped up
C7.6- What is the product of the reaction in a hydrogen fuel cell?
Water
Carbon dioxide
Hydrogen
Hydrogen peroxide
C7.6- What type of reaction is the following?
Combustion
Neutralisation
Oxidation
Reduction
C7.6- How can you tell the following reaction is a reduction?
Electrons are being removed
Electrons are being added
Water is being made
There are an even number of chemicals
C7.6- Which of these is NOT an advantage of a hydrogen fuel cell?
It does not produce any pollutant gases
It reacts chemicals electrochemically so is more efficient than combustion
The reactants are easy to obtain
They are much faster to refuel than electric vehicles
C7.6- Which of these is NOT a disadvantage of hydrogen fuel cell cars?
They don't travel as far between refuellings as petrol engines
Hydrogen is very explosive so difficult to store
There are not many hydrogen refuelling points
The engine gets dangerously hot
