Daffodil International University

Faculties and Departments => Faculty Sections => Departments => Topic started by: ABM Nazmul Islam on October 25, 2014, 01:13:08 PM

Title: keep glass joints and stopcocks away from caustic soda
Post by: ABM Nazmul Islam on October 25, 2014, 01:13:08 PM

Glass reacts slowly with aqueous sodium hydroxide solutions at ambient temperatures to form soluble silicates. Because of this, glass joints and stopcocks exposed to sodium hydroxide have a tendency to "freeze". Flasks and glass-lined chemical reactors are damaged by long exposure to hot sodium hydroxide, which also frosts the glass. Sodium hydroxide does not attack iron since iron does not have amphoteric properties (i.e., it only dissolves in acid, not base). A few transition metals, however, may react vigorously with sodium hydroxide.