Page 141 - Pharmaceutical Analytical Chemistry III
P. 141
• Colloidal ppts tend to peptize if washed
with pure water because water will
dilute and remove electrolytes.
• Peptization is the reverse of
coagulation
Electrolyte
• Colloidal solution Coagulated ppt
Peptization
To prevent peptization, add electrolyte to the
washing liquid (eg: volatile HNO3 or NH4OH)
