Chapter 9:Industrial Inorganic chemistry

Question 1

Describe the production of iron:

Answer 1

1. coke burns in hot air to form CO2
2. more coke reacts with CO2 to form CO (stronger reducing agent)
3. CO reduces iron (iii) oxide to iron
4. limestone is added to the furnace to remove impurities
5. calcium oxide reacts with silicon dioxide to form calcium silicate (slag)

Question 2

Process of steel-making:

Answer 2

1. furnace is charged with scrap steel and molten iron
2. oxygen is blown in
3. molten steel and slag is poured into the furnace by tilting it in different directions

Question 3

Uses of mild steel:

Answer 3

car bodies
chains
machinery

Question 4

Uses of stainless steel:

Answer 4

cutlery
kitchen sinks
medical instruments

Question 5

What is rust?

Answer 5

a red-brown powder consisting of Fe2.H2O (iron that has been oxidized)

Question 6

What are some methods of preventing rust?

Answer 6

-painting
-oiling or greasing
-plastic coating or electroplating
-galvanizing
-sacrificial protection

Question 7

What is galvanizing?

Answer 7

A method of preventing rust where a metal is coated with a more reactive metal that will be oxidized first.

Question 8

What is sacrificial protection?

Answer 8

A method of preventing rust where a more reactive metal is attached to the metal and the more reactive metal will sacrifice itself and react first.

Question 9

Describe the extraction of Zinc:

Answer 9

Extracted from zinc blende.
1. Zinc blende is heated strongly with air 2ZnS + 3O2 —->2ZnO + 2SO2
2. coke reduces ZnO to Zn
3. Zinc vapor (boils at 907 degrees) is cooled and condensed

Question 10

What are some of the uses of Zinc?

Answer 10

galvanizing and making brass

Question 11

What is the process of the extraction of aluminum from bauxite?

Answer 11

1. bauxite is treated with sodium hydroxide to obtain pure aluminum oxide.
2. aluminum oxide is mixed with molten cryolite to reduce the high melting point of aluminum from 2000 to 1000 degrees.
3. molten mixture of aluminum oxide and cryolite is electrolyzed.
   Al 3+ + 3e- —–> Al (cathode)
   2O 2- —-> O2 +4e-

Question 12

What are some general properties of ammonia gas?

Answer 12

colorless gas
distinctive smell
less dense than air
soluble in water to form an alkaline solution

Question 13

What is the test for ammonia gas?

Answer 13

damp red litmus paper turns blue

Question 14

What are the components of most fertilizers?

Answer 14

nitrogen: greens up plants
potassium: helps produce blooms
phosphates and phosphorous: overall good for the plants

Question 15

Describe the process of the contact process:

Answer 15

1. burn sulfur in air S + O2 –> SO2
2. mixture of gases reacted using a catalyst at 450 degrees and a few atm pressures
   2SO2 + O2 <—> 2SO3
3. gas is then slowly absorbed into concentrated sulfuric acid
   SO3 + H2SO4 —> H2S2O2
   H2S2O2 + H2O —> 2H2SO4

Question 16

What is the Chlor-Alkali industry?

Answer 16

the industrial process for the electrolysis of sodium chloride solutions.
hydrogen and chlorine gas are produced and a solution of sodium hydroxide is left

Question 17

What is the limestone cycle?

Answer 17

a thermal decomposition reaction.
limestone (CaCO3) heat——-> Quicklime (CaO) water added ——-> Slaked lime (Ca(OH)2) carbonated——> Limestone (CaCO3)

Question 18

What are some uses of limestone?

Answer 18

cement
concrete
neutralize acidic soils
steel manufacture to remove impurities
water treatment and purification
white pigment

Question 19

What is the process of making lime (CaO) ?

Answer 19

limestone is heated with hot air and rolled to produce CaO and CO2