unit 16- industrial process

Question 1

State what is a Haber process

Answer 1

the process used to make ammonia

Question 2

Describe Haber process

Answer 2

Reactants are nitrogen and hydrogen. Nitrogen is obtained from air. Hydrogen is obtained by cracking hydrocarbons. The two gases are mixed and scrubbed(cleaned) to remove impurities. The gas mixture is compressed(200 atm) and passed over the bed of hot iron ( 450 degrees celsius). The mixture of nitrogen, hydrogen, and ammonia is cooled until the ammonia condenses to a liquid. Ammonia is stored as a liquid. The remaining nitrogen and hydrogen are turned back to the hot iron bed.

Question 3

Condition of Haber process

Answer 3

450 degrees Celcius and 200 atmospheres, with iron.

Question 4

How to improve yield in Haber process

N2 + 3H2 ⇌ 2NH3

backward reaction is endothermic

Answer 4

High pressure, remove ammonia, lower temperature.

Question 5

Will the yield in reversible reaction ever be 100%

Answer 5

No

Question 6

Ways to get a decent reaction rate in Haber process

Answer 6

Catalyst ( Iron), moderate temperature

Question 7

Effect of iron in the Haber process in yield and reaction rate

Answer 7

Same yield, higher reaction rate.

Question 8

Why do we need ammonia

Answer 8

To make fertiliser

Question 9

Where is sulfur found

Answer 9

around volcanos or in the fossil fuels as a compound

Question 10

Uses of sulfur

Answer 10

make sulfuric acid, make papers, shampoos

Question 11

Why is sulfur dioxide bad to us if we release it into atmosphere

Answer 11

It causes acid rain

Question 12

What is contact process

Answer 12

the process for making sulfuric acid

Question 13

Describe contact process

Answer 13

Sulfur is burned in air to form sulfur dioxide. Sulfur dioxide is mixed with more air and passed over catalyst ( vanadium (V) oxide at 450 degree celcius ), some of the sulfur dioxide combine with oxygen molecules to form sulfur trioxide. Sulfur trioxide is dissolved into concentrated sulfuric acid to make oleum. Then mixed carefully with water to form concentrated sulfuric acid.

Question 14

What is the optimum condition for contact process,and explain for the reason in detail

Answer 14

450 degree celcius 1-2 atmosphere. 450 degree is used even though yield of SO3 decreases as temperature increases, because the catalyst will not work below 400 degree celsius. and the rate of reaction will be slow if the temperature is low. Only 1-2 atm is used even though yield of SO3 increases as pressure increases, because the yield is already high enough and it’s dangerous if the pressure is high.

Question 15

Uses of sulfuric acid

Answer 15

fertilisers, paints

Question 16

Why is sulfur trioxide in contact process is converted into oleum, and give chemical formula for oleum

Answer 16

Oleum is easier to transport and store it. H2S2O7

Question 17

Where can limestone obtain from, and give its chemical formula

Answer 17

From shells and skeletons of sea creatures. CaCO3

Question 18

How is lime produce from limestone, give chemical equation

Answer 18

Thermal decomposition of limestone, it breaks down into lime and carbon dioxide.
CaCO3 ⇌ CaO + CO2

Question 19

How is slacked lime made from lime, give chemical fomular for slacked lime and its uses

Answer 19

Add water. Ca(OH)2. Flue gas desulfurisation, neutralise acidic soil

Question 20

Uses of crushed limestone

Answer 20

extract iron from iron ore

Question 21

Uses of powerdered limestone

Answer 21

Neutralise acidic soil

Question 22

How is cement made and how is it used

Answer 22

Heat limestone with clay, used to make concrete.

Question 23

What is flue gas desulfurisation

Answer 23

Removal of sulfur dioxide from the waste gases at power station

Question 24

How is gypsum formed

Answer 24

Add calcium hydroxide with sulfur dioxide to from calcium sulfite and water. Add oxygen and water to calcium sulfite to form gypsum.( hydrated calcium sulfate).