keep glass joints and stopcocks away from caustic soda

Author Topic: keep glass joints and stopcocks away from caustic soda  (Read 342 times)

Offline ABM Nazmul Islam

  • Sr. Member
  • ****
  • Posts: 386
  • Test
    • View Profile
keep glass joints and stopcocks away from caustic soda
« 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.
ABM Nazmul Islam

Lecturer
Dept. of Natural Science
Daffodil Int. University, Dhaka, Bangladesh