Rates of Reaction

Question 1

what is meant by the rate of a chemical reaction?

Answer 1

how fast the reactants are turned into products

Question 2

how is the rate of reaction measured?

Answer 2

amount of reactant used OR amount of product formed
/
time

units = g/s or cm^3/s

Question 3

what is activation energy?

Answer 3

the minimum amount of energy that particles must have when they collide before they will react

Question 4

what are the five main factors affecting rate of reaction?

Answer 4

1. temperature of the reaction mixture
2. the concentration of a solution
3. the pressure of a gas
4. the surface area of a solid
5. the addition of a catalyst

Question 5

describe the effect of surface area on reaction rate

Answer 5

the larger the surface area the higher the rate of reaction

Question 6

what is the effect of temperature on rate of reaction

Answer 6

the higher the temperature the higher the rate of reaction

Question 7

the effect of pressure on rate of reaction

Answer 7

increasing pressure increases the rate of reaction

Question 8

define the term catalyst

Answer 8

a substance that increases the rate of reaction of a mixture without being used up itself

Question 9

what is the effect of a catalyst on rate of reaction

Answer 9

a catalyst increases the rate of reaction

Question 10

why are catalysts used in industrial processes?

[give examples of catalysts and the reactions they are used in]

Answer 10

• more product can be made in a shorter period of time = more product
• catalysts can be reused
• less heat is required

[EXAMPLES]
iron is a catalyst in the haber process which produces ammonia
nickel is a catalyst in the hydrogenation of oils to form margarine
enzymes are biological catalysts which speed up the chemical reactions in living things