Sodium Hydroxide氢氧化钠.pdf

416/Sodium Hydroxide/ Monographs
CC V
in which 27 is an empirically determined equivalence factor Insoluble Substances and Organic Matter A 1: 20 aqueous
for D-lucose and are the volume and normality, respec- solution Is complete, clear, and colorless to slightly colored
tively, of the iodine solution; and 2 and N are the volume Lead Determine as directed under Lead Limit fest, Appen
and normality, respectively, of the sodium thiosulfate solution. dix IB, usin 2 wg of lead P)ion in the control and the
following as the Sample So/ation: Dissolve I g of sample in
Packaging and Storage Store in well-closed containers
a mixture of 5 ML of water and II ML of 2.7 N hydrochloric
acid and cool
Mercury Determine as directed under Mercury Limit Test
Appendix IIB, preparing the S/andard Preparation and the
Sample Preraration as follows
Sodium Hvdroxide
Standard Preparation Prepare a solution containing I wg
of mercury per milliliter as directed in Standard Preparation
austic Soda, Lye
under Mercu Limit Test, Appendix IIB, Transfer 1.0 ml
o[ the solution into a 50-ml beaker and add 20 ml o water
NAOH
Formula wt 40.00
id. and 1 ML of a 1: 25 solution of
INS: 524
CAS:L1310-73-2
potassium permanganate. Cover the beaker with a watch glass
boi for a few se
d
Sample Preparalion Transfer 10.0 g of sample into a
100-ML beaker, dissolve in 15 ML of water, add 2 drops
DESCRIPTION
of phenolphthalein TS, and while constantly stirring, slowly
neutralize with 1: 2 hydrochloric acid. Add I ml of 1: 5 sulfuric
Sodium Hydroxide occurs as white or nearly while pellets, acid and I ml of a 1: 25 solution of potassium permanganate
nlakes, sticks, fused masses, or other forms. Upon exposure
to air it readily absorbs carbon dioxide and moisture. One
cover the beaker with a watch glass, boil for a few seconds
gram dissolves in I ML of water. Il is freely soluble in alcohol
and cool
Packaging and Storage Store in tight containers
Function ph control agent
REQUIREMENTS
Identification A 1: 25 aqueous solution gives positive tests
Sodium Hydroxide Solutions
for Sodium, Appendix IIIA
Assay Not less than 95.0% and not more than 100.5%o of
Caustic Soda Solutions; Lye Solutions
total alkali calculated as NAOH
Arsenic Nol more than 3 mg/kg
Carbonate (as Na, CO? Not more than 3.0%
Insoluble Substances and Organic Matter Passes test
DESCRIPTION
Lead Nol more than 2 mg/kg
Sodium Hydroxide Solutions occur as clear or slightly turbid
Mercury Not more than 0.1 mg/k
colorless or slightly colored liquids. They are usually available
Itions of 50% and 73%(w/w)of NAOH
TESTS
These solutions are strongly caustic and hygroscopic. W
Assay Dissolve about 1.5 g of sample, accurately weighed
exposed to air, they absorb carbon dioxide, forming sodium
carbonate
in 40 ML of recently boiled and cooled water, cool to 15
add phenolphthalein TS, and titrate with I N sulfuric acid
When the pink color disappears, record the volume of acid
Function PH control agent
required, then add methyl orange TS, and continue the titration
until a persistent pink color appears. Record the total volume
REQUIREMENTS
of acid required for the titration. Each milliliter of I Sulfuric Labelin