3b-Rates of reaction

Question 1

Question: What is the rate of a chemical reaction?

Answer 1

Answer: The rate of a chemical reaction is the speed at which reactants are converted into products.

Question 2

Question: How can the rate of reaction be measured?

Answer 2

Answer:

Measure the decrease in mass of reactants over time.

Measure the volume of gas produced using a gas syringe.

Measure the time taken for a precipitate to form, making a solution cloudy.

Question 3

Question: What factors affect the rate of a reaction?

Answer 3

Answer:

Temperature

Concentration of reactants

Surface area of solids

Pressure (for gases)

Presence of a catalyst

Question 4

Question: How does temperature affect the rate of reaction?

Answer 4

Answer: Increasing temperature gives particles more energy, making them move faster and collide more frequently with enough energy, increasing the reaction rate.

Question 5

Question: How does concentration affect the rate of reaction?

Answer 5

Answer: Higher concentration means more particles in a given volume, increasing the frequency of collisions and speeding up the reaction.

Question 6

Question: How does surface area affect the rate of reaction?

Answer 6

Answer: Larger surface area (e.g., using smaller particles) increases the number of exposed particles, leading to more frequent collisions.

Question 7

Question: How does pressure affect the rate of reaction in gases?

Answer 7

Answer: Higher pressure compresses gas particles into a smaller volume, increasing collision frequency and speeding up the reaction.

Question 8

Question: What is the role of a catalyst?

Answer 8

Answer: A catalyst speeds up a reaction by lowering the activation energy without being consumed in the process.

Question 9

Question: What is activation energy?

Answer 9

Answer: Activation energy is the minimum energy required for particles to collide successfully and cause a reaction.

Question 10

Question: What is the collision theory?

Answer 10

Answer: Collision theory states that particles must collide with sufficient energy and the correct orientation to react.

Question 11

Practical: Investigating the Effect of Concentration on Reaction Rate

Method:

Answer 11

Add dilute hydrochloric acid to a flask containing marble chips (calcium carbonate).

Measure the volume of carbon dioxide gas produced using a gas syringe.

Repeat with different concentrations of acid.

Question 12

Practical: Investigating the Effect of Concentration on Reaction Rate

Results& conclution

Answer 12

Results:

Higher concentrations produce gas more quickly, indicating a faster reaction rate.

Conclusion:

Increasing concentration increases the frequency of collisions, speeding up the reaction.