Chemistry Flashcards
What is the rate of reaction?
The speed at which reactants are converted into products in a chemical reaction.
Measured by the change in concentration of reactants or products over time.
How is the rate of reaction measured?
By observing the change in concentration of reactants or products over a specific time period.
Common methods include measuring gas produced, color change, or mass loss.
What factors affect the rate of a chemical reaction?
Temperature, concentration, surface area, and the presence of catalysts.
Each factor influences the frequency and energy of collisions between reactant particles.
What is collision theory?
A theory that states that for a reaction to occur, reactant particles must collide with sufficient energy and proper orientation.
Emphasizes the importance of effective collisions in chemical reactions.
What is activation energy?
The minimum energy required for a reaction to occur.
It represents the energy barrier that must be overcome for reactants to form products.
How can a reaction be slowed down?
By decreasing temperature, lowering concentration, reducing surface area, or adding inhibitors.
Inhibitors are substances that decrease the rate of reaction.
How does temperature affect the rate of reaction?
Increasing temperature generally increases the rate of reaction.
Higher temperatures increase particle movement and collision frequency.
What happens to particle movement when temperature increases?
Particles move faster and have more kinetic energy.
This leads to more frequent and effective collisions.
How does temperature influence activation energy?
Higher temperatures can provide particles with more energy to overcome the activation energy barrier.
Thus, reactions are more likely to occur.
What is the relationship between temperature and collision frequency?
As temperature increases, collision frequency also increases.
More collisions result in a higher rate of reaction.
Why do reactions happen faster at higher temperatures?
Because particles have more kinetic energy, leading to more frequent and energetic collisions.
This increases the likelihood of overcoming activation energy.
What is the Maxwell-Boltzmann distribution?
A statistical distribution that describes the energy distribution of particles in a gas.
It illustrates how many particles have sufficient energy to react at different temperatures.
How does surface area affect the rate of reaction?
Increased surface area leads to a higher reaction rate.
More surface area allows for more collisions between reactants.
Why do smaller particles react faster than larger particles?
Smaller particles have a larger surface area relative to their volume.
This increases the number of collisions and speeds up the reaction.
What happens to the collision rate when surface area increases?
The collision rate increases.
More particles are exposed for potential collisions.
How does crushing a solid reactant change the reaction rate?
Crushing increases the surface area, leading to a faster reaction rate.
This facilitates more frequent collisions.
What is an example of a reaction where surface area is important?
The combustion of powdered metals versus solid chunks.
Powdered metals burn faster due to increased surface area.
How does surface area impact industrial reactions?
Larger surface areas can enhance reaction rates, leading to more efficient processes.
This is crucial in industries such as pharmaceuticals and materials manufacturing.
What is a catalyst?
A substance that increases the rate of a reaction without being consumed.
Catalysts work by lowering the activation energy required for the reaction.
How does a catalyst speed up a reaction?
By providing an alternative pathway with a lower activation energy.
This increases the number of effective collisions.
Why do catalysts lower activation energy?
They facilitate the formation of the transition state, requiring less energy to reach it.
This makes the reaction proceed faster.
What is an example of a catalyst in industry?
Iron in the Haber process for ammonia synthesis.
Catalysts are essential for increasing efficiency in chemical manufacturing.
What is an enzyme?
A biological catalyst that accelerates biochemical reactions.
Enzymes are crucial for processes in living organisms.
Why are catalysts not used up in a reaction?
They are regenerated at the end of the reaction cycle.
This allows them to be used repeatedly.
