EXOTHERMIC & ENDOTHERMIC
REACTION RATES
COLLISION THEORY
100
1. An exothermic reaction:
A. Absorbs heat from the surroundings
B. Releases heat to the surroundings
C. Does not involve energy changes
D. Stops when the temperature rises
B. Releases heat to the surroundings
100
Which factor generally causes particles to move faster?
A. Lower temperature
B. Higher temperature
C. Smaller surface area
D. Lower concentration
B. Higher temperature
100
According to collision theory, a reaction can only occur when reactant particles:
A. Touch each other
B. Change colour
C. Dissolve in water
D. Form a gas
A. Touch each other
200
During an exothermic reaction, the temperature of the surroundings usually:
A. Decreases
B. Stays the same
C. Increases
D. Becomes zero
C. Increases
200
A powdered solid reacts faster than a large lump of the same solid because it has:
A. Lower mass
B. More energy
C. Greater surface area
D. Higher density
C. Greater surface area
200
A collision that produces a reaction is called:
A. Random collision
B. Successful collision
C. Neutral collision
D. Physical collision
B. Successful collision
300
If a reaction absorbs heat from its surroundings, the temperature of the surroundings will:
A. Increase
B. Stay the same
C. Decrease
D. Double
C. Decrease
300
Increasing the concentration of a reactant solution increases the reaction rate because:
A. There are fewer particles present
B. Particles move more slowly
C. There are more particles available to collide
D. The reaction becomes endothermic
C. There are more particles available to collide
300
Most collisions between particles are unsuccessful because:
A. The particles are too small
B. The particles are too large
C. They do not have enough energy to react
D. They always miss each other
C. They do not have enough energy to react
400
A student mixes two chemicals and notices that the beaker becomes colder. This suggests that the reaction is:
A. Exothermic because energy is released
B. Endothermic because energy is absorbed
C. Exothermic because products have more energy
D. Neither exothermic nor endothermic
B. Endothermic because energy is absorbed
400
Two identical reactions are carried out. Reaction A uses marble chips, while Reaction B uses powdered marble. All other conditions are the same. Why does Reaction B occur faster?
A. The powder has a higher temperature
B. The powder contains more particles
C. The powder provides a larger surface area for collisions
D. The powder changes the reaction type
C. The powder provides a larger surface area for collisions
400
A reaction mixture is heated and stirred. According to collision theory, why does the reaction rate increase?
A. Particles become heavier and collide less often
B. There are fewer collisions but more products
C. Particles collide more frequently and a higher proportion of collisions are successful
D. All collisions become successful regardless of energy
C. Particles collide more frequently and a higher proportion of collisions are successful