Manufacture of Ammonia - Haber's process

Question 1

Reactants

Answer 1

Nitrogen
Hydrogen
1:3 ratio by volume

Question 2

Product :

Answer 2

Ammonia - 2 volumes

NH3

Question 3

Conditions

Reaction :

Answer 3

Reversible
Exothermic
Proceeds with a - decrease in volume
Low temperature and high pressure - favour the forward reaction

Question 4

Temperature

Pressure

Answer 4

450- 500*

200-900 atmospheres

Question 5

Catalyst :

Answer 5

Finely divided Iron [Fe]

Question 6

Promoter :

Answer 6

Molybdenum

Question 7

Precaution :

Answer 7

Impurities like CO , CO2 , H2S may poison the catalyst

Hence the nitrogen - hydrogen reactant mixture must be free from them

Question 8

Reactant Nitrogen gas is obtained by

Answer 8

Fractional distillation of liquid air

Question 9

Reactant hydrogen obtained from

Answer 9

Water [ Bosch process ]

Question 10

Higher ratio of hydrogen -

Answer 10

or an increase in concentration of the reactant favors the forward reaction to give optimum yield of ammonia

Question 11

Reactant should be free from impurities

Answer 11

Pure and dry since impurities tend to poison the catalyst and reduce effectiveness

Question 12

Temperature

above this optimum temperature what will happen

Answer 12

Ammonia may decompose to give nitrogen and hydrogen

Question 13

Why external heat is not required?

Answer 13

after the reactant are initially

since its exothermic the evolved is further maintains the temperature

Question 14

if a reaction proceeds with decrease in volume

Answer 14

then the forward reaction is favoured by increasing pressure

Question 15

What happens if the pressure is too high ?

Answer 15

the production plant can’t withstand the pressure

Question 16

Why catalyst is required?

Answer 16

to accelerate the reaction

Question 17

Catalyst job

Answer 17

only accelerates the reaction
does not form a part of reaction
does not affect the percentage of yield of ammonia

Question 18

ammonia is seperated from uncombined Nitrogen and Hydrogen
Liquefaction :
Ammonia is easily ______
it condenses to a liquid at ________
_______ and __________ are difficult to liquefy
they are condense at temp at ___________ and _________

Answer 18

Liquefiable
-33*C at 8 atmos press
N2 , H2
-196 C , -253C