Rate of reaction *

Question 1

What is the rate of reaction?

Answer 1

the change that happens in a single unit of time

Question 2

How do you calculate the rate of reaction (2 ways)

Answer 2

amount of reactant used / time
amount of product used / time

Question 3

What factors affect the rate of reaction? (5 factors)

Answer 3

temperature, concentration, surface area, pressure, catalyst

Question 4

Collision theory - fill the gaps :
- for a reaction, particles have to _______
- if they _______ with enough ______ they _____
- the minimum amount of energy needed for a ________ is called the __________ ______
- the rate of reaction depends on the number of __________ _______

Answer 4

• for a reaction, particles have to collide
• if they collide with enough energy they react
• the minimum amount of energy needed for a reaction is called the activation energy
• the rate of reaction depends on the number of successful collisions

Question 5

Effect of temperature - fill the gaps :
- increased temperature gives particles more ______
- increases ________ of particles
- particles _______ more ________, with more _____
- increases ____ of _______

Answer 5

• increased temperature gives particles more energy
• increases movement of particles
• particles collide more frequently, with more force
• increases rate of reaction

Question 6

Effect of concentration - fill the gaps :
- increased concentration increases _______ of particles
- increases ________ of ______
- increases ____ of _______

Answer 6

• increased concentration increases number of particles
• increases frequency of collisions
• increases rate of reaction

Question 7

Effect of surface area - fill the gaps :
- increased surface area to volume ratio of a solid reactant increases ________ of ______
- increases ____ of _______
so :
the more _____ _____ a solid is, the _____ the reaction happens
(higher _____ ____ __ ___ ____)

Answer 7

• increased surface area to volume ratio of a solid reactant increases frequency of collisions
• increases rate of reaction

the more finely divided a solid is, the faster the reaction happens
(higher surface area to volume ratio)

Question 8

Effect of increasing pressure - fill the gaps :
- increasing pressure increases the _____ of molecules per unit _____
- increases ________ of ________
- increases ____ of _______

Answer 8

• increasing pressure increases the number of molecules per unit volume
• increases frequency of collisions
• increases rate of reaction

Question 9

What is a catalyst?

Answer 9

a catalyst speeds up the rate of a reaction without being used up or chemically changed

Question 10

Effect of catalysts - fill the gaps :
- a catalysts provides a _____ where particles can ____ on
- increases _______ of ______
- catalysts provide an __________ ________ with a lower _______ ______ than the original ________
- particles react with less _____ than they needed before

Answer 10

• a catalysts provides a surface where particles can react on
• increases frequency of collisions
• catalysts provide an alternate pathway with a lower activation energy than the original pathway
• particles react with less energy than they needed before