Premium
The influence of water on the rhythmic process of precipitation of ammonium chloride formed by the counterdiffusion of ammonia and hydrogen chloride
Author(s) -
Davies G. A.,
Ponter A. B.,
Singh S.
Publication year - 1971
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450490114
Subject(s) - precipitation , ammonia , ammonium chloride , chemistry , nucleation , diffusion , chloride , hydrogen chloride , moisture , ammonium , inorganic chemistry , hydrogen , thermodynamics , organic chemistry , meteorology , physics
Abstract Results are reported for the formation of ammonium chloride by counter diffusion of ammonia and hydrogen chloride over the temperature range 25 ‐ 40°C. Two modes of precipitation were observed, continuous and periodic precipitation (formation of Liesegang rings). The results establish that the presence of moisture is the important factor controlling the mechanism of precipitation, a minimum moisture content of approximately 100 ppm being required for formation of Liesegang rings. Under these conditions the concentration product was found to be very much greater than the thermodynamic minimum value confirming that nucleation of the solid product regulates the process.