C5.2

Question 1

What is rate of reaction?

Answer 1

Rate of reaction:

• The speed of the reaction

Question 2

What is the equation for calculating rate of reaction?

Answer 2

Equation for rate of reaction:

• Rate of reaction = quantity of reactant used /
  time taken
• Rate of reaction = quantity of product formed/
  Time taken

Question 3

How do you calculate rate of reaction for gases?

Answer 3

Rate of reaction for gases:

1) Gas is produced and travels to the syringe
2) Plunger will move as gas pushes it out
3) Measure rate of reaction by dividing how much the plunger moved by the time

Question 4

What is the collision theory?

Answer 4

Collision theory:

• Chemical reactions only occur when reacting particles collide with sufficient energy with each other

Question 5

How does temperature increase the rate of reaction?

Answer 5

Temperature increasing rate of reaction:

• Heating substances increases temperature
• Giving more energy to the particles
• More energy means faster movement
• Faster movements mean more likely for particles to collide with each other
• When they collide, they have more energy in the collision
• Meaning enough energy available to react

Question 6

What is concentration?

Answer 6

Concentration:

• Number of particles dissolved in a given volume of solvent

Question 7

What is pressure?

Answer 7

Pressure:

• Number of particles in a given volume of gas

Question 8

How does more concentration and pressure increase rate of reaction?

Answer 8

Concentration and pressure increasing rate of reaction:

• More particles in the same space
• Means more FREQUENT collisions take place

Question 9

What is surface area?

Answer 9

Surface area:

• The outside surface that is exposed to the reaction

Question 10

Why do large lumps decrease rate of reaction?

Answer 10

Large lumps decreasing rate of reaction:

• Lower surface area : volume ratio
• Fewer particles of the solid exposed the the solution

Question 11

Why does powder increase rate of reaction?

Answer 11

Powder increasing rate of reaction:

• Higher surface area : volume ratio
• More frequent collisions

Question 12

What is a catalyst?

Answer 12

Catalyst:

• Substance that speeds up chemical reaction without being used up itself
• Increases rate of reaction
• Reduces activation energy
• Less energy required

Question 13

How does a catalyst work?

Answer 13

Catalyst works:

• Provides different pathway for reaction that has lower activation energy
• Change amount of energy needed for successful collisions