| Sodium is a very soft, silvery white metal. It is so soft that it can
be easily cut with a knife. Compounds of sodium are very common, but the
metal itself cannot be found in nature in its pure form. Pure sodium metal
has virtually no practical application since it reacts vigorously under
normal environmental conditions. It is so reactive that the pure metal
has to be stored in containers filled with a non reactive liquid such as
kerosene.
It is used for medicine, agriculture, and photography. Sodium
is the 6th most abundant element in the world. Sodium makes table
salt. If a sodium atom collides with a chlorine atom an electron
passes from the former to the latter. The sodium atom with an electron
gone, now has only 10 electrons to balance the 11 protons in the nucleus.
There is one positive charge left over. Therefor the sodium atom has a
charge of +1 and the Chlorine atom has a charge of -1.
There are many different sodium compounds that are useful. Listed below
are some common ones:
1. sodium bromide, NaBr. This compound is used in medicine and
photography.
2. sodium chlorate, NaClO3. This is a powerful oxidizing agent.
It is used in explosives, in matches, as
a weed killer, and in the textile industry.
3. sodium chloride, NaCl. This is also known as table salt.
4. sodium hydroxide, NaOH. This compound is used in the chemical
industry. The only common
household application is as a drain cleaner.
5. sodium bicarbonate, NaHCO3. This is also known as baking
soda. It is used as a leavening in bakery
products, in stomach antacids, in effervescent
beverages, and as a fire extinguishing agent.
6. sodium carbonate, NaCO3. This compound is called "washing
soda" because of its use in water
softening. It is also commonly used as a cleaning
agent and bleach.
7. sodium hexametaphosphate, Na2[Na4(PO3)6]. This is also known
as Calgon. Calcium ions in water
can be prevented from precipitating with soap
or forming boiler scale by tying them up in soluble
complex ions with the use of Calgon.
8. sodium cyanide, NaCN. This is used in the steel industry.
Large amounts of this highly toxic
compound are used each year to case-harden
steel.
9. sodium nitrate, NaNO3. This is a common component in fertilizers
and explosives.
10. sodium sulfate, NaSO4. Depending upon its water content,
they have different names:
anhydrous sodium sulfate, NaSO4,
is free of water. It is used as a drying agent in chemistry
laboratories.
sodium sulfate decahydrate, NaSO4.10H2.
This is known as Glauber's salt. It is used in the
manufacture of glass and as a
purgative in medicine.
11. sodium thiosulfate, Na2S2O3. This compound is used in photography
as "hypo". |
