community
directory
books
authors
images
encyclopedia

Email:
Password:
Register

Knowledgerush Search

 

Google
  Web knowledgerush


Search for images of NaOH


Message boards   Post comment

NaOH

Properties

General

Name Sodium hydroxide
Chemical formula NaOH
Appearance White solid

Physical

Formula weight 40.0 amu
Melting point 596 K (323 °C)
Boiling point 1663 K (1390 °C)
Density 2.1 ×103 kg/m3
Crystal structure ?
Solubility ?

Thermochemistry

ΔfH0gas -197.76 kJ/mol
ΔfH0liquid -416.88 kJ/mol
ΔfH0solid -425.93 kJ/mol
S0gas, 1 bar 228.47 J/mol·K
S0liquid, 1 bar 75.91 J/mol·K
S0solid 64.46 J/mol·K

Safety

Ingestion May cause severe and permanent damage to the GI system.
Inhalation Irritation for low exposures, may be harmful or fatal in higher doses.
Skin Dangerous. Symptoms range from mild irritation to nasty ulcers.
Eyes Dangerous. May cause burns, damage to cornea or conjuctiva.
More info Hazardous Chemical Database
SI units were used where possible. Unless otherwise stated, standard conditions were used.

Disclaimer and references

Sodium hydroxide (NaOH), also known as caustic soda or lye in North America, is a caustic metallic base used in industry (mostly as a strong chemical base) in the manufacture of paper, textiles, and detergents.

Sodium hydroxide is occasionally used in the home as an agent for unclogging stuck drains, but it is highly caustic and has a high danger of causing chemical burns, permanent injury or scarring, and blindness, due to its high reactivity. So, store it separately.

When sodium hydroxide reacts with water and fluids, it can become hot enough to cause fires. For this reason, it is important to have the proper type of chemical fire extinguisher on hand before working with sodium hydroxide. Store this product in an airtight container to prevent NaOH from absorbing water and CO2 from the air. It can create enough heat to ignite flammables (such as alcohols), so add slowly in biodiesel processor.

Sodium hydroxide is manufactured by electrolysis of an aqueous solution of sodium chloride. It is a by-product of the process that is used to make chlorine.

A solution of a small portion of lye diluted in water is used in the traditional method of making a pretzel. It is also a traditional ingredient in the making of soap, and for this purpose was historically obtained in an impure form by steeping wood ash in water for a long period.

Biodiesel
For biodiesel, this is one of the main reactants, like catalyst. Make sure you are purchasing anhydrous sodium hydroxide, because water turns biodiesel into soap (saponification).

However, it is more used than potassium hydroxide, KOH, because it dissolves in methanol much more easily than NaOH, and it doesn't "clump".

Another alternative in the future is to use sodium silicate instead of sodium hydroxide.

Lutefisk
Lye is also used when preparing the Swedish delicacy known as Lutefisk, which is basically codfish jellied in lye.

French
The french name for lye is "soude caustique".

Spanish
The spanish name for sodium hydroxide is "potasa"

Referenced By

How to make Biodiesel | Hygroscopic | Potasium hydroxide | Potassium hydroxide | Soap | Soap and water

 

Compose Your Message

Your Email Address or Pen Name (optional):
Subject:
Your Message:
 

 

 

 

 

 

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "NaOH".

 

Contact UsPrivacy Statement & Terms of Use

 
Copyright © 1999-2003 Knowledgerush.com. All rights reserved.