Energy Changes in Chemical Reactions - SS1 Chemistry Past Questions and Answers - page 1
Which of the following best describes an exothermic reaction?
A reaction that absorbs heat from the surroundings
A reaction that releases heat to the surroundings
A reaction that involves a change in temperature
A reaction that occurs spontaneously
Which of the following is an example of an exothermic process?
Melting ice to form liquid water
Photosynthesis in plants
Electrolysis of water
Dissolving salt in water
In an exothermic reaction, which of the following is true?
The products have a higher energy than the reactants
The reaction absorbs heat from the surroundings
The reaction feels cold to the touch
The enthalpy change (∆H) is negative
Which of the following best describes an endothermic reaction?
A reaction that absorbs heat from the surroundings
A reaction that releases heat to the surroundings
A reaction that involves a change in temperature
A reaction that occurs spontaneously
Which of the following is an example of an endothermic process?
Combustion of gasoline
Condensation of water vapour
Freezing of water to form ice
Mixing an acid and a base to form water and salt
In an endothermic reaction, which of the following is true?
The products have a higher energy than the reactants
The reaction releases heat to the surroundings
The reaction feels hot to the touch
The enthalpy change (∆H) is positive
Which of the following factors can influence the extent of heat released or absorbed in a reaction?
Temperature
Concentration of reactants
Catalysts
All of the above
The enthalpy change (∆H) for an exothermic reaction is:
Positive
Negative
Zero
Variable, depending on the reaction
The enthalpy change (∆H) for an endothermic reaction is:
Positive
Negative
Zero
Variable, depending on the reaction
Which of the following is a common example of an exothermic reaction?
Rusting of iron
Photosynthesis
Melting of wax
Cooking an egg