C6 C7 Rate of Reaction and Energy Changes

Activation energy is required to start a chemical reaction. What is activation energy?

• The energy needed for a reaction to occur
• The minimum amount of energy needed for a reaction to potentially occur
• The energy added by a catalyst
• The energy possessed by the products

Tags

NGSS.HS-PS1-4

Increase in temperature of the reactants can do one of the following

• Slow collision frequency
• Allow less effective collision between the particles
• Cause particles to lose speed
• Increase frequency of effective collision between the particles thus increasing the rate of reaction.

Tags

NGSS.HS-PS1-5

Decreasing the particle size increases the reaction rate because

• It makes particles move faster
• It increases the likelihood of collisions with the correct geometry
• It decreases the surface area available to react
• It increases the surface of the reactants thus more particles collides with each other therefore increase the frequency of effective collisions

Grinding a seltzer tablet into powder increases the rate of reaction due to increased

• concentration
• surface area
• temperature
• reactants

Tags

NGSS.HS-PS1-5

Increasing the concentration increases the speed of reaction by

• lowering activation energy
• increasing number of particles collisions thus increase in frequency of effective collision
• speeding up the reactants
• exposing more reactant

Which factors increase the rate of a reaction.

• increasing temperature
• increasing concentration
• increasing surface area
• all of these

Tags

NGSS.HS-PS1-5

Calcium carbonate reacts with hydrochloric acid to form carbon dioxide. Which changes would slow this reaction down?
 1  decreasing the concentration of hydrochloric acid
 2  decreasing the particle size of calcium carbonate
3  decreasing the temperature 

• 1 and 2 only 
• 1 and 3 only 
• 2 and 3 only 
• 1, 2 and 3 

Tags

NGSS.HS-PS1-5

As temperature increases, what happens to the reacting particles?

• The particles become closer together.
• The particles gained kinetic energy and starts moving faster. 
• There are more particles per unit volume. 
• The particles increase in size. 

Tags

NGSS.HS-PS1-5

Which of the following statements about the effect of increasing temperature on a chemical reaction is correct?

• It increases the yield of the product. 
• It provides an alternative pathway for the reaction to occur. 
• It causes the particles to increase in size.
• It increases the speed of the reaction. 

Tags

NGSS.HS-PS1-5

What type of reaction is this?

• Endothermic
• Exothermic

Tags

NGSS.HS-PS1-4