Rate of Reaction

Question 1

what is the rate of a reaction

Answer 1

the change in the concentration of the product or reactant over unit time

Question 2

how is the volume of gas given off in the ‘volume of gas given off’ method measured with

Answer 2

a gas syringe

Question 3

How can you find the rate of reaction from a graph?

Answer 3

The gradient

Question 4

What is the relationship between rate and time?

Answer 4

They are inversely proportional; the faster the rate the shorter the time

Question 5

What does collision theory state?

Answer 5

That reactions can only occur if particles collide.
The particles must collide with enough energy to react
The particles must collide with the correct orientation

Question 6

Activation Energy

Answer 6

thethe minimum energy required for substances to break tthe bond in the reactant anf enale paraticles to form products

Question 7

4 factors that affect rates of reaction

Answer 7

Temperature
Concentration of solutions
Surface area of solids
Using a catalyst

Question 8

How does surface area increase the rate of reaction?

Answer 8

(small particle= large SA) Increasing the SA, exposes more of the surface. This means more frequent collisions in the same time and this increases the rate of reaction.

Question 9

How does temperature effect the rate of reaction?

Answer 9

Temperature increases the speed of the particles, so they collide more often and with more energy. They also reach the activation energy required much quicker. This increases the rate of reaction

The rate is not directly proportional to temperature

Question 10

Roughly by how much will the rate of reaction will increase by if the temperature is increased by 10 degrees?

Answer 10

Double

Question 11

How does the concentration effect the rate of reaction?

Answer 11

A higher concentration means more particles are dissolved in the same volume, meaning the particles are closer together and so collide more often

The rate of reaction is directly proptioanl to the concentration

Question 12

what is a cataylst

Answer 12

A catalyst is a substance which alter the rate or reaction of a chemical

Question 15

How do catalysts work?

Answer 15

They lower the activation energy as they provide an alternative pathway at a lower energy level so more successful collisions occur ^^ meaning they speed up reactions

Question 15

what is a endothermic reaction

Answer 15

a reaction which takes in energy from the surroundings, usually in the form of heat and is usually shown by a fall in temperature of the surroundings

Question 16

what would happen if the energy input is less than the activation energy

Answer 16

there wont be enough energy to start a reaction, so nothing would happen

Question 17

what is an exothermic reaction

Answer 17

a reaction which gives out energy to its surroundings, usually in the form of heat and usually shown by a rise in temperature of the surroundings