Worksheets6.2 Energy in Chemical Reactions
Total questions: 25
Worksheet time: 14mins
What is one of the most important features of chemical reactions?
They produce large amounts of energy.
They produce large amounts of water.
They produce large amounts of oxygen.
They produce large amounts of carbon dioxide.
What form of energy do all molecules store?
Kinetic energy
Thermal energy
Chemical potential energy
Electrical energy
What happens to atoms and molecules during chemical reactions?
They remain the same
They disappear
They rearrange and release energy
They become larger
What type of reaction is it usually if a chemical reaction has oxygen as a reactant?
Endothermic
Exothermic
Neutral
Catalytic
What is an example of a combustion reaction that releases heat?
Ice melting
Water boiling
Fire burning
Photosynthesis
What is a combustion reaction?
A. A reaction where a substance burns in oxygen to produce light and heat.
B. A reaction where a substance dissolves in water.
C. A reaction where a substance freezes.
D. A reaction where a substance evaporates.
What type of reaction is a fire an example of?
A. Combustion reaction
B. Freezing reaction
C. Dissolution reaction
D. Evaporation reaction
What does a combustion reaction release?
A. Light and heat
B. Cold and darkness
C. Water and ice
D. Smoke and fog
What are the two elements that make up hydrocarbons?
C and H
C and O
H and O
C and N
What is the product of the combustion of a hydrocarbon in the presence of oxygen?
CO2 and H2O
CO and H2
C and H2O
CO2 and O2
What is the primary function of respiration in the body?
To release energy for the body
To produce glucose
To store oxygen
To create carbon dioxide
What are the end products of respiration when glucose and oxygen react?
Glucose and water
Carbon dioxide and water
Oxygen and carbon dioxide
Water and oxygen
In the respiration reaction, what gas is required along with glucose?
CO2
O2
H2O
N2
What is one of the byproducts of respiration that helps keep the body warm?
Light
Sound
Heat
Electricity
What is the main purpose of respiration in the body?
To release energy for the body
To produce glucose
To absorb carbon dioxide
To create oxygen
What are the products of the respiration reaction?
Glucose and oxygen
Carbon dioxide and water
Oxygen and water
Glucose and carbon dioxide
Which of the following is a reactant in the respiration process?
Water
Carbon dioxide
Glucose
Nitrogen
What is the process called when most metals combine with oxygen gas to form metal oxides?
Combustion
Corrosion
Oxidation
Reduction
Which of the following is the correct reaction for metals combining with oxygen gas?
metal + oxygen gas → metal oxide
metal + hydrogen gas → metal hydride
metal + nitrogen gas → metal nitride
metal + carbon dioxide → metal carbonate
What is the process called when iron reacts with oxygen and water to form hydrated iron(III) oxide?
Combustion
Rusting
Photosynthesis
Fermentation
6. Which of these processes is always exothermic?
A. evaporation
B. burning
C. insulation
D. melting
In an endothermic reaction, heat is ...
taken in
given out
A student mixed two chemicals to allow them to react. The temperature before the reaction was 25 ° C. The temperature after the reaction was 18° C. Which of the following is true?
It is an exothermic reaction
It is an endothermic reaction
