AARYANS WORLD SCHOOLSubject-Science

Topic-Acids ,bases and saltsSub-topic- Salts

By-Ishwari S. PanseStd.-X

What are salts?

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 electrically neutral. 

What are salts?

What are the properties of salts?

ColourSalts can appear to be clear and transparent (sodium chloride), opaque, and even metallic and lustrousTasteDifferent 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).Odourstrong salts are non-volatile and odorless, weak salts may smell after the conjugate acid or the conjugate base of the component ions.

What are the properties of salts?

How are salts formed ?

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

How are salts formed ?

How are salts used

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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.

How are salts used ?

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.

How are salts used ?

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 product.

How are salts used ?

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.

How are salts used ?

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 mesh.

How are salts used ?

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 its own.

How are salts used ?

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.

How are salts used ?

GENERAL COOKING - Fine salt is used for all sorts of cooking and is similar to table salt, without the addition of Sodium Silico Aluminate.

How are salts used ?

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 sodium fluoride.

How are salts used ?

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.

How are salts used ?

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.

How are salts used ?

SWIMMING POOLS -Swimming pool salt is designed specifically for use with salt pool chlorinators.

How are salts used ?

SYNTHETIC RUBBER 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 medium quality.

How are salts used ?

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.

How are salts used ?

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.

How are salts used ?

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.

How are salts used ?

OTHER USES -Other uses of salt include butter manufacture, soil stabilisation, tempering of steel, fertilisers and weed killers, and pine board manufacture.

How are salts used ?

Thank you