Question 1
Where does an exothermic reaction transfer energy?
-
To the surroundings
-
From the surroundings
-
Into the reactants
-
Into the catalyst
Question 2
Where does an endothermic reaction take energy from?
-
The surroundings
-
The products
-
A catalyst
-
New atoms
Question 3
What usually happens to the surroundings during an exothermic reaction?
-
Temperature increases
-
Temperature decreases
-
Temperature stays unchanged
-
Temperature first falls then rises
Question 4
What usually happens to the surroundings during an endothermic reaction?
-
Temperature decreases
-
Temperature increases
-
Temperature stays unchanged
-
Temperature first rises then falls
Question 5
Which process is typically exothermic?
-
Combustion
-
Thermal decomposition
-
Photosynthesis
-
Melting
Question 6
Which process is typically endothermic?
-
Thermal decomposition
-
Condensation
-
Freezing
-
Neutralisation
Question 7
What energy change usually occurs when an acid reacts with an alkali?
-
Exothermic
-
Endothermic
-
No overall energy change
-
A physical change
Question 8
How is photosynthesis classified?
-
Endothermic because it absorbs light energy
-
Exothermic because it releases oxygen
-
Exothermic because glucose stores energy
-
Endothermic because it absorbs carbon dioxide
Question 9
How is cellular respiration classified?
-
Exothermic reaction
-
Endothermic reaction
-
Physical change
-
Reversible change
Question 10
What happens to energy when chemical bonds break?
-
Energy is absorbed
-
Energy is released
-
Energy is unchanged
-
Energy becomes a catalyst
Question 11
What happens to energy when chemical bonds form?
-
Energy is released
-
Energy is absorbed
-
Energy is unchanged
-
Energy becomes a reactant
Question 12
Which bond-energy balance makes a reaction exothermic?
-
Making bonds releases more than breaking bonds absorbs
-
Breaking bonds absorbs more than making bonds releases
-
Making and breaking bonds transfer equal energy
-
Activation energy is greater than product energy
Question 13
Where are products shown on an exothermic reaction profile?
-
Lower than the reactants
-
Higher than the reactants
-
Level with the reactants
-
At the activation-energy peak
Question 14
What is activation energy?
-
The minimum energy needed for particles to react
-
The total energy released in all reactions
-
The energy stored in products
-
The energy needed to cool a reaction
Question 15
How does a catalyst speed up a reaction?
-
It provides a lower-activation-energy pathway
-
It increases the mass of reactants
-
It raises the energy of products
-
It is used up to release extra heat
Question 16
Which setup best measures a reaction's temperature change?
-
Insulated cup, lid and thermometer
-
Uninsulated beaker and thermometer
-
Insulated cup and stopwatch
-
Metal tray and balance
Question 17
Which change of state is endothermic?
-
Melting
-
Freezing
-
Condensation
-
Deposition
Question 18
Which change of state is exothermic?
-
Condensation
-
Boiling
-
Sublimation
-
Melting
Question 19
Why does an instant cold pack feel cold?
-
Its reaction absorbs thermal energy from the skin
-
Its reaction releases thermal energy to the skin
-
Its contents evaporate from the skin
-
Its insulation prevents energy transfer
Question 20
What is the symbol equation for the burning of methane?
-
\(\mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O}\)
-
\(\mathrm{CH_4 + O_2 \rightarrow CO + H_2}\)
-
\(\mathrm{CH_4 + 2O_2 \rightarrow C + 2H_2O}\)
-
\(\mathrm{2CH_4 + O_2 \rightarrow 2CO_2 + 2H_2O}\)
Question 21
Where are products shown on an endothermic reaction profile?
-
Higher than the reactants
-
Lower than the reactants
-
Level with the reactants
-
At the activation-energy peak
Question 22
What does the vertical difference between reactants and products show?
-
The overall energy change
-
The activation energy
-
The reaction rate
-
The catalyst mass
Question 23
Which energy store supplies energy when a fuel burns?
-
Chemical store
-
Thermal store
-
Kinetic store
-
Gravitational store
Question 24
Why can a catalyst be reused?
-
It remains chemically unchanged
-
It becomes one of the products
-
It stores the activation energy
-
It increases in mass during reaction
Question 25
Why put a lid on a reaction calorimeter?
-
Reduce thermal transfer to the surroundings
-
Increase the reaction's activation energy
-
Make the thermometer respond faster
-
Prevent the reactants forming bonds
Question 26
Why repeat a reaction temperature experiment?
-
Identify anomalies and calculate a mean
-
Increase the reaction's energy change
-
Lower the activation energy each time
-
Make the products more stable
Question 27
A reaction warms from 18 °C to 25 °C. What is the temperature change?
-
7 °C
-
43 °C
-
−7 °C
-
1.4 °C
Question 28
Why does a chemical hand warmer feel hot?
-
An exothermic reaction transfers energy to the skin
-
An endothermic reaction takes energy from the skin
-
Melting absorbs energy from the skin
-
Insulation creates thermal energy inside it
Question 29
If a forward reaction is exothermic, how is its reverse reaction classified?
-
Endothermic
-
Exothermic
-
No energy change
-
A physical change
Question 30
What does the rise from reactants to the peak of a reaction profile show?
-
The activation energy
-
The overall energy change
-
The reaction temperature
-
The product mass