Page 241 - Chemistry ICSE Class X

Study of Compounds–Ammonia 227
ƒ Reactants. Nitrogen (N ), Hydrogen (H )
2
2
ƒ Products. Ammonia (NH )
3
ƒ Reaction: N (g) + 3H (g) 2NH (g)
2
2
3
nitrogen hydrogen ammonia
The nitrogen required for the reaction is obtained from the air, while
hydrogen is obtained from water gas (Bosch process).
ƒ Plant and the process. Plant used in the Haber’s process is shown in
Fig. 9.4.
A mixture of nitrogen and hydrogen in the ratio 1 : 3 is compressed to
CDQWV CVO RTGUUWTG 6JG EQORTGUUGF ICU KU VJGP CNNQYGF VQ GPVGT
the converter. Converter is a chrome-vanadium steel pressure vessel. The
ECVCN[UV RCEMGF KP VJG EQPXGTVGT KU MGRV CV u% 6JG COOQPKC UQ
HQTOGF KU NKSWGſGF QP EQQNKPI 6JG WPTGCEVGF PKVTQIGP CPF J[FTQIGP CTG
recirculated through the converter.

Fig. 9.4 Plant for Haber’s process
ƒ Recovery of ammonia. +P *CDGTŏU RTQEGUU CDQWV Ō QH VJG
reacting gases (N and H ) are converted to ammonia.
2
2
Ammonia is recovered from the mixture of nitrogen, hydrogen and
ammonia by liquefaction or by dissolving it in water.
The unreacted nitrogen and hydrogen gases are recirculated through
the converter.

Physical and Chemical Properties of Ammonia

What are the physical properties of ammonia

ƒ Colour, odour, taste. Ammonia gas is a colourless gas with a pungent
odour and an alkaline taste.
ƒ Solubility. #OOQPKC ICU KU JKIJN[ UQNWDNG KP YCVGT XQNWOG
XQNWOG CV u% CPF UQ cannot be collected over water.
The high solubility of the gas can be demonstrated by the fountain
experiment.

The fountain experiment
+P VJG HQWPVCKP GZRGTKOGPV C TQWPF DQVVQO ƀCUM KU FTKGF CPF ſNNGF YKVJ
COOQPKC ICU 6JG ƀCUM KU ſVVGF YKVJ C EQTM UWRRQTVKPI C FTQRRGT EQPVCKPKPI
a little amount of water, and with a long jet reaching near the bottom of
VJG ƀCUM 6JG QRGP GPF QH VJG LGV KU KOOGTUGF KPVQ VJG YCVGT EQPVCKPKPI C
small amount of red litmus. A little quantity of water is then introduced into