AARYANS WORLD SCHOOL
Topic-Acids ,bases and salts
By-Ishwari S. Panse
Salts are ionic compounds that result from
the neutralization reaction of an acid and a base.
They are composed of related numbers
of cations and anions so that the product is
Salts can appear to be clear and transparent (sodium chloride), opaque,
and even metallic and lustrous
Different salts can elicit all five basic tastes, e.g., salty (sodium chloride),
sweet (lead diacetate,), sour (potassium bitartrate), bitter (magnesium
sulfate), and savory (monosodium glutamate).
strong salts are non-volatile and odorless,
weak salts may smell after the conjugate acid or the conjugate base of
the component ions.
Salts are formed by a chemical reaction between:
† A base and an acid,
e.g., NH3 + HCl → NH4Cl
† A metal and an acid,
e.g., Mg + H2SO4 → MgSO4 + H2
†A metal and a non-metal,
e.g., Ca + Cl2 → CaCl2
ALUMINIUM PURIFICATION- Salt is used
as a flux. The salt sits on top of the molten
aluminium in molten salt form, this
removes iron and other metals from
aluminium leaving pure metal.
BREAD AND PASTRY - Salt is used to
give added flavour to bread and
pastry. The main requirement here is
that the product, either flossy or
superfine, is clean and free from any
extraneous matter. Salt also performs
a function in controlling the rate at
which the yeast works in the dough,
giving a better texture to the bread.
CANNING OF MEAT AND VEGETABLES -
Salt is added to the products during
processing and it is essential in these
cases that the salt be free of drit, and
particularly free of any specks or iron
particles as these show up in the finished
CAUSTIC/CHLORINE MANUFACTURE - The
conversion of salt to form caustic soda
and chlorine requires a crude salt with
very high chemical purity. Salt is dissolved
to form brine and the impurities are
removed chemically before the brine
passes into the electrolytic cells.
CHEESE MANUFACTURE- Most cheese
today is made on automatic machines
and salting must be carried out in a
continuous process. The salt used must
be extremely dry at all times and
contain virtually no fines beyond 60
DRILLING -Salt is used to mix with boring
mud which is pumped down bore holes to
form a wall when drilling through gravel or
sandy material which will not stand up on
FISH & MEAT CURING - This is usually
carried out by dissolving salt to form a
strong brine to act as a pickle. The
products may be placed in the pickle,
or in many cases the pickle is pumped
into the actual meat (such as in the
case of bacon and ham). Salt for these
purposes should be refined grades,
clean and of high quality.
GENERAL COOKING - Fine
salt is used for all sorts of
cooking and is similar to table
salt, without the addition of
Sodium Silico Aluminate.
HIDE CURING -Hides and sheep skins
are normally salted with a reasonably
low quality salt. Hide salts are usually
only washed grades but contain certain
additives such as boric acid, to keep
the hide as light a colour as possible.
Other additives are naphthalene and
POTTERY PRODUCTION -Salt is used to
form the very smooth glaze on clay tiles or
pottery ware. After a kiln of tiles reaches a
yellow to white heat, salt is then fed on to
the fire. The salt vaporises and passes on
to the surface of the tile, actually forming
a glass surface.
SOAP & GLYCERINE MANUFACTURE- Fats and
oils are saponified by heating with caustic
soda to produce soap and glycerine. The soap
is "grained" or "salted out" from solution by
adding salt or strong brine.
SWIMMING POOLS -Swimming pool
salt is designed specifically for use
with salt pool chlorinators.
MANUFACTURE - Synthetic
rubber is produced in the form
of white latex to which salt is
added as an emulsifier. Salt for
this purpose is in crude form, of
TABLE SALT -This is a specially
prepared salt for domestic
purposes, with small, even
crystals. Sodium Silico
Aluminate is added as a free
flowing agent. Table salt also
comes in iodised form.
TEXTILE DYEING -Salt is added to the dye
baths during the process mainly to make
the dyes fast. Flossy salt is the grade most
commonly used in this process.
WATER SOFTENING -Salt is used in
both industrial and home water
softening units. The purpose being to
regenerate the resins which pick up
the objectionable salts in the normal
water supply. Salt for this purpose is
usually a washed or refined grade. A
similar type of salt is used for making
a brine for brine cooling systems.
OTHER USES -Other uses of salt include
butter manufacture, soil stabilisation,
tempering of steel, fertilisers and weed
killers, and pine board manufacture.