7D Sulphuric Acid

Question 1

Discovery of Sulpuric Acid

Answer 1

Initially prepared by Distilling green vitriol

Question 2

Sulphuric Acid was inititally called

Answer 2

Oil of Vitriol

Question 3

Formula of Green Vitriol

Answer 3

FeSO4.7H2O

Question 4

Why was it called oil of vitriol?

Answer 4

Prepared by distilling green vitriol

Question 5

Occurence:

Answer 5

Free and Combined State

Question 6

Free state of Sulphuric Acid:

Answer 6

Minute traces in hot springs

Near Sulphide beds. Ex: Hydrolysis of iron pyrites

Question 7

Combined State:

Answer 7

Salts in minerals

Metallic Sulphates

Question 8

4 General methods of preparation:

Answer 8

1. By action of heat on nitric acid and sulphur
2. By passage of chlorine through an aqueous solution of sulphur dioxide
3. By dissolution of sulphur trioxide in water
4. By hydrolysis of sulphuryl chloride

Question 9

First Method

Answer 9

1. Action of Heat on nitric acid and Sulphur
   S + HNO3 —–> NO2 + H2O + H2SO4
   (Conversion of Nitric acid to non-volatile sulphuric acid)

Question 10

Second Method:

Answer 10

2. By passage of chlorine through an aqueous solution of sulphur dioxide
   Cl2 + SO2 + H2O —-> 2HCl + H2SO4

Question 11

Third Method:

Answer 11

3. By dissolution of sulphur trioxide in water

SO3 + H2O —–> H2SO4

Question 12

Fourth Method:

Answer 12

4. By hydrolysis of sulphuryl chloride

SO2Cl2 + 2H2O —-> H2SO4 + HCl

Question 13

Manufucture of Sulphuric Acid is by

Answer 13

Contact Process

Question 14

What are the parts of the unit in contact Process:

Answer 14

1. Production of SO2
2. Purification Unit
3. Catalytic Oxidation
4. Absortpion of SO3
5. Dilution of Oleum

Question 15

2. Purification Unit contains:

Answer 15

1. Dusting Tower
2. Cooling Pipes
3. Scrubbing tower
4. Drying Tower
5. Arsenic Purifier
6. Testing Box

Question 16

1. Production of SO2 Contains:

Answer 16

1. Blower

2. Sulphur or Pyrite Burners

Question 17

3. Catalytic Oxidation Contains:

Answer 17

1. Contact Tower

Question 18

4. Absorption of SO3 Contain

Answer 18

Aabsorption Tower

Question 19

5. Dilution of Oleum Contains:

Answer 19

Dilution Tank

Question 20

Use of
1. Production of SO2
A. Blower

Answer 20

For passage of purified air or Oxygen

Question 21

Use of
1. Production of SO2
B. Sulphur or Pyrite Burners

Answer 21

For production of sulphur dioxide by burninng sulphite or iron pyrites

Question 22

Use of

2. Purification Unit:

Answer 22

Purification of Gaseios mixture of SO2 and o2

Question 23

Use of
2. Purification Unit:
C. Dusting tower:

Answer 23

For removal of dust particles by downward blow of steam

Question 24

Use of
2. Purification Unit:
D. Cooling Pipes

Answer 24

For cooling of gases bby passage through isolated pipes

Question 25

Use of
2. Purification Unit:
E. Scrubbing Tower:

Answer 25

For further removal of impurities and dust particles by downward sprpay of water

Question 26

Use of
2. Purification Unit:
F. Drying tower:

Answer 26

For drying moist gases by downward spray of conc. H2SO4

Question 27

Use of
2. Purification Unit:
G. Arsenic Puifier:

Answer 27

For removing arsenic oxide bby passage over ferric hydroxide

Question 28

Use of
2. Purification Unit:
H. Testing box

Answer 28

For testing the purity of the gases by passage of light through a darkened box

Question 29

Use:
3. Catalytic Oxidation:
I. Contact Tower

Answer 29

For Catalytic oxidation of 
 - SO2 to SO3
By passage of sulphur dioxide and oxygen thrugh iron tower
packed with vanadium pentoxide catalyst
initially heated to 450

Question 30

Use:
4. Absorption of SO3:
J. Absorption Tower:

Answer 30

For absorption of sulphur trioxide vapors by descending stream of con. H2SO4 (98%)

Question 31

Use:
5. Dilution of Oleum
Dilution Tank:

Answer 31

For dilution of Oelum by flow of requisite amount of soft water

Question 32

Reactions at Contact Process:

What are the 3 steps?

Answer 32

1. Sulphur or Pyrite burners
2. Contact Tower
3. Absorption Tower

Question 33

Reactions at Contact Process:

Step 1:

Answer 33

Chamber: Sulphur or Pyrite Burners
Conversion: Production of Sulphur dioxide by burning sulphur or iron pyrites [FeS2]
S + O2 —-> SO2
FeS2 + O2 —-> Fe2O3 + SO2

Question 34

Reactions at Contact Process:

Step 2:

Answer 34

Chamber: Contact Tower
Conversion: Catalytic Oxidation of Sulphur Dioxide to Sulphur trionide
2SO2 + O2 —-> (V2O5, 450 to 500, 1 to 2 Atmos) SO3 + Heat
[Above equation for the catalysed reaction is exothermic, hence supplies energy]

Question 35

Reactions at Contact Process:
Step 2:
Catalyst:

Answer 35

Vanadium Pentoxide
[V2O5]
[Pt]

Question 36

Reactions at Contact Process:
Step 2:
Temperature:

Answer 36

450 to 500

Question 37

Reactions at Contact Process:
Step 2:
Pressure:

Answer 37

1 to 2 atmospheres

Question 38

Reactions at Contact Process:
Step 2:
Conversion Ratio:

Answer 38

98% of sulphur dioxide converted to sulphur Trioxide

Question 39

Reactions at Contact Process:

Step 3:

Answer 39

Chamber: Absorption Tower
Conversion: Absorption of sulphur trioxide in 98% sulphuric acid to give oleum or pyrosulphuric acid [H2S2O7]

Question 40

Reactions at Contact Process:

Dilution Tank:

Answer 40

Dilution of oleum with calculated amount of sodt water to give sulphuric acid of the desired concentration.
H2S2O7 + H2O —–> H2SO4

Question 41

Contact Process:

1. Sulphur or Pyrite Burners

Answer 41

Sulphur Dioxide is obtained by burning sulphur or iron pyrites

Question 42

Sulphur Dioxide is obtained by burning sulphur or iron pyrites

Answer 42

1. When Sulphur is burnt in air, it burns with a pale blue flame forming sulphur dioxide and traces of sulphur trioxide

S + O2 —-> SO2
[S + O2 —-> SO3]

Question 43

Why is burning Sulphur or iron pyrites in oxygen is preferred to purifies air?

Answer 43

Heat energy is wasted in heating the unreactive nitrogen component of the air

Question 44

2. Purification Unit:

Answer 44

The gaseous mixture of sulphur dioxide and oxygen [air] are passed through a purification unit before entering the contact tower

Question 45

2. Purification Unit:

Impurities present:

Answer 45

The gaseous mixture of SO2 and O2 contains impurities mainly dust particles or pyrites dust and arsenious oxide

Question 46

2. Purification Unit:

Reason For removal of Impurities:

Answer 46

The impurities if not removed tend to deactivate or posion the catalyst and thereby reduce it efficiency

Question 47

2. Purification Unit:

Method of removal of impurities:

Answer 47

The dust particles are removed in the dusting and scrubbing tower and the arsenious oxide {Passage over Fe(OH3)

Question 48

Physical properties of Sulphuric acid

Color

Answer 48

Colorless

Question 49

Physical properties of Sulphuric acid

Odour

Answer 49

Odourless

Question 50

Physical properties of Sulphuric acid

Taste

Answer 50

Slight odour taste

Question 51

Physical properties of Sulphuric acid

Nature

Answer 51

Dense,Oily, hygroscopic liquid

[Being hygroscopic it absorbs moisture from the atmosphere and hence is kept in airtight container

Question 52

Physical properties of Sulphuric acid

Density

Answer 52

Heavier than water
Pure acid (specific gravity1.85

Question 53

Physical properties of Sulphuric acid

Solubility

Answer 53

Soluble in water in all proportions

Question 54

Physical properties of Sulphuric acid

Constant boiling mixture

Answer 54

Forms a constant boiling mixture boiling at 338 degree celcius containing 98.5 percent of the acid

Question 55

Physical properties of Sulphuric acid

Boiling point

Answer 55

338 degree celcius

[B.P. of liquid HCl is -83 degree celcius and dilute Nitric acid is 86 degree celcius}

Question 56

Physical properties of Sulphuric acid

Melting point

Answer 56

Freezes to colorless crystals having m.p. 10.4 degree celcius

Question 57

Physical properties of Sulphuric acid

Conductivity

Answer 57

Pure acid:Almost a non-conductor of electricity

Dilute acid:Good conductor of electricity