Chemistry chapter 9 (Reversible Reactions and Equilibrium)

Question 1

What is the color change of Hydrated Copper (II) Sulfate

Answer 1

From White to Blue

Question 2

What is the color change of Hydrated Cobalt (II) Chloride

Answer 2

From Blue to Pink

Question 3

How to remove water from Hydrated Copper (II) Chloride?

Answer 3

Heat up the mixture slowly until the water evaporates off.

Question 4

Name 2 tests for pressance of water.

Answer 4

Anhydrous Copper (II) Sulfate, Anhydrous Cobalt (II) Chloride

Question 5

Define Anhydrous

Answer 5

It means Containing no Water

Question 6

Define Reversible reactions.

Answer 6

A chemical reaction that can go either forward or backward depending on the condition.

Question 7

What is a Closed System?

Answer 7

A system when no reactants or products can escape from the reaction mixture.

Question 8

Under what condition is chemical equilibrium achieved in an open system?

Answer 8

Under the condition that none of the reactants and products are in gaseous state. (The reaction happens entirely in liquid)

Question 9

What is Dynamic (Chemical) Equilibrium?

Answer 9

When reactants are continuously combining to make products at the same time and at the same rate, the products are breaking and turning back into the reactants.

Question 10

Rule of Dynamic Equilibrium?

Answer 10

. Rate of Forward reaction = Rate of Backward reaction
. Amount of Products and Reactants remain constant but not necessarily the same

Question 11

What happens to the reaction in a dynamic equilibrium when one of its reaction conditions change?

Answer 11

The system reacts in such a way as to oppose the effect of the change. By 𝐦𝐨𝐯𝐢𝐧𝐠 𝐭𝐡𝐞 𝐩𝐨𝐬𝐢𝐭𝐢𝐨𝐧 𝐨𝐟 𝐭𝐡𝐞 𝐞𝐪𝐮𝐢𝐥𝐢𝐛𝐫𝐢𝐮𝐦.

Question 12

Name 3 factors affecting the position of the equilibrium.

Answer 12

Concentration, Temperature, and Pressure

Question 13

The Effects on the position of the Equilibrium by changing the concentration.

Answer 13

> 𝐈𝐧𝐜𝐫𝐞𝐚𝐬𝐞 concentration of reactants = Moves to the 𝐫𝐢𝐠𝐡𝐭
𝐃𝐞𝐜𝐫𝐞𝐚𝐬𝐞 concentration of reactants = Moves to the 𝐥𝐞𝐟𝐭
𝐈𝐧𝐜𝐫𝐞𝐚𝐬𝐞 concentration of products = Moves to the 𝐥𝐞𝐟𝐭
𝐃𝐞𝐜𝐫𝐞𝐚𝐬𝐞 concentration of products = Moves to the 𝐫𝐢𝐠𝐡𝐭

Question 14

What is considered when researching effect of pressure on Equilibrium?

Answer 14

The number of gaseous molecules only

Question 15

The Effects of Pressure on the position of the Equilibrium?

Answer 15

> Increase Pressure = Moves to the side with fewer gaseous Molecules
Decrease Pressure = Moves to the side with more Gaseous Molecules.

Question 15

The Effects of Pressure on the position of the Equilibrium?

Answer 15

> 𝐈𝐧𝐜𝐫𝐞𝐚𝐬𝐞 Pressure = Moves to the side with 𝐅𝐞𝐰𝐞𝐫 gaseous Molecules
𝐈𝐧𝐜𝐫𝐞𝐚𝐬𝐞 Pressure = Moves to the side with 𝐌𝐨𝐫𝐞 Gaseous Molecules.

Question 16

Effects of Increasing Temperature on the Position of Equilibrium.

Answer 16

> Exothermic = Moves to the left
Endothermic = Moves to the right

Question 17

Effects of Decreasing Temperature on the Position of Equilibrium.

Answer 17

> Exothermic = Moves to the right
Endothermic = Moves to the left

Question 18

What does the direction of movement regarding Temperature depend on?

Answer 18

It depends on the sign of the enthalpy change.

Question 19

How do catalysts work?

Answer 19

They work by providing an alternative reaction pathway involving a lower activation energy.

Question 20

How do catalysts affect the equilibrium?

Answer 20

They DO NOT affect the position of the equilibrium but they do increase the rate that equilibrium is obtained.

Question 21

What is the Contact process?

Answer 21

The industrial manufacture of sulfuric acid using the raw materials sulfur and air.

Question 22

What is Harbor process?

Answer 22

The process used to produce ammonia, used in manufacturing fertilizers.

Question 23

Conditions of the Haber process (Ammonia production)

Answer 23

.Pressure = 20,000 kPa (200 atmospheres)
.Temperature = 350-450℃
.Catalyst = Iron

Question 24

What does the Equilibrium theory favor for the Haber process?

Answer 24

i) Low temperature- Exothermic reaction (Higher yield at lower temperature)

ii) High pressure- Moves to the fewer gaseous molecules (RHS)

Question 24

What does the Equilibrium theory favor for the Haber process?

Answer 24

i) Low temperature- Exothermic reaction (Higher yield at lower temperature)

ii) High pressure- Moves to the fewer gaseous molecules (RHS)

Question 25

6 key facts of Haber process.

Answer 25

i) H2 and N2 are mixed in a 3:1 ratio
ii) Because the reaction is not reversible not all the nitrogen and hydrogen will convert to ammonia.
iii) The ammonia forms as a gas but cools and liquifies in the condenser,
iv) The H2 and N2 which do not react are passed through the system again, so they are not
wasted.
v) The ammonia stored is stored as liquid under pressure.
vi) Most of the ammonia produced is used to manufacture fertilisers.

Question 26

Properties of Ammonia?

Answer 26

. It is a colourless alkaline gas
. It is an irritant with a characteristic pungent odour
. It is highly soluble in water

Question 27

Uses of Ammonia?

Answer 27

. About 90% of ammonia produced is used in fertilizer
. It is also used in the manufacture of many products including nylon, nitric acid, pesticides and dyes.

Question 28

Conditions for contact process?

Answer 28

. Pressure = 200kPa (2 atmospheres)
. Temperature = 450℃
. Catalyst = Vanadium (v) oxide

Question 29

What does the Equilibrium theory favor for the Contact process?

Answer 29

.Low temperature- Exothermic reaction (Higher yield at lower temperature)
.High pressure- Move to the fewer gaseous molecules (RHS)

Question 30

Stages of making sulfuric acid.

Answer 30

Stage 1- Making sulfur dioxide
Stage 2- Making sulfur Trioxide
Stage 3- Converting sulfur
trioxide into sulfuric acid

Question 31

Explain stage 1 of making Sulfuric acid.

Answer 31

.Sulfur is burned into the air to make sulfur dioxide
.It should not be releases as it contributes to acid rain

Question 32

Explain stage 2 of making Sulfuric acid.

Answer 32

.Reacts with more oxygen to make sulfur trioxide
.Catalyst- Vanadium(v) oxide (V2O5)
.Temperature- 450℃
.Pressure- 150kPa
(1.5 atmospheres)

Question 33

Explain stage 3 of making Sulfuric acid.

Answer 33

.Cannot be simply mixed with water as the reaction is uncontrollable
.Must be dissolved in concentrated Sulfuric acid to make oleum (H2S2O7)
.Oleum can then be mixed with water to safely make Sulfuric acid, twice the amount used to make the oleum.

Question 33

Explain stage 3 of making Sulfuric acid.

Answer 33

.Cannot be simply mixed with water as the reaction is uncontrollable
.Must be dissolved in concentrated Sulfuric acid to make oleum (H2S2O7)
.Oleum can then be mixed with water to safely make Sulfuric acid, twice the amount used to make the oleum.

Question 33

Uses of Sulfuric Acid.

Answer 33

i) It is used to make fertilizers. This is done by reacting the sulfuric acid with ammonia, or ammonium hydroxide solution, to make Ammonium Sulfate.
ii) It is also used in making detergents, paints, fertilizers, fibers, dyes, soaps, etc.

Question 34

Define Fertiliser.

Answer 34

Any material of natural or synthetic origin added to the soil to supply one or more plant nutrients.

Question 35

Why are most fertilizers called nitrogenous?

Answer 35

Because they have a high nitrogen content.

Question 36

What are NPK fertilizers?

Answer 36

Fertilizers that contain compounds of nitrogen, phosphorus and potassium

Question 37

Use of Nitrogen in plants?

Answer 37

Healthy leaves

Question 38

Use of Potassium in plants?

Answer 38

Production of flowers and fruits

Question 39

Use of Phosphorous in plants?

Answer 39

Healthy roots

Question 40

What are NPK fertilizers usually a mixture of?

Answer 40

They are a mixture of Ammonium Nitrate, Ammonium phosphate and Potassium chloride

Question 41

What has to be done to Ammonia for it to turn to a fertilizer?

Answer 41

They have to mix it with an acid as it is a very strong alkali and has to be neutralised

Question 42

How to prevent fertilizer from making the soil acidic?

Answer 42

By mixing it with chalk (Calcium Carbonate), which will neutralize the effects

Question 43

What are some problems caused by Soluble fertilizers?

Answer 43

They can be washed away by rainwater into rivers and lakes. This cause pollution resulting in fish dying and algal blooms (Green coating) covering water.

Question 44

Examples of Organic fertilizers.

Answer 44

Animal waste and Compost

Question 45

2 features of equilibrium.

Answer 45

i) Rate of forward reaction = backward reaction
ii) Concentration of Reactant and Product remains constant.