Some important metals and their Uses
- Metals are good conductors of heat & electricity and are malleable and ductile.
- Gold and silver are most malleable and best ductile metals.
- Silver is the best conductor of heat followed by copper.
- Aluminium and copper are good conductors of heat that’s why cooking utensils are made of them.
- Mercury offers high resistance to the flow of electric current.
- Sodium and potassium are so soft that they can be easily cut with knife.
- Metals are electropositive in nature.
- Almost all the metal oxide are basic in nature but zinc oxide and aluminium oxide are amphoteric.
Alkali metals and their compounds
- Metals of first group are alkali metals.
- This group lies in the s-block of the periodic table of elements as all alkali metals have their outermost electron in an s-orbital.
- Lithium, sodium, potassium, rubidium and cesium are alkali metals.
- These metals are stored under kerosene or liquid paraffin’s to protect them from action of air.
Sodium chloride (NaCl):
- Commonly known as table salt
- Used in the manufacturing of sodium hydroxide and chlorine gas.
- It is used as a starting material in the manufacturing of caustic soda.
- It is used in the removing of ice from road, now a- days CaCl2 and MgCl2 are also used for this purpose.
Sodium hydroxide (NaOH):
- Used in the refining of bauxite material.
- Used in soap, dyes and artificial industries.
Sodium bicarbonate (NaHCO3):
- It is commonly known as baking soda.
- Used for wool washing.
- Used in the fire extinguisher.
Sodium carbonate (Na2CO3)
- It is commonly known as washing soda.
- Used for softening of hard water.
- Mixture of sodium carbonate and potassium carbonate is known as Fusion mixture.
- It is commonly known as Glauber’s salt.
- It is used as purgative.
- It is commonly known as Hypo and used in the photography as fixing agent.
- It is known as pearl ash.
- Commonly known as caustic potash.
- Use in the preparation of soft soap.
- Its aqueous solution is known as potash Iye.
- Used in space capsules, submarines and breathing mask as it removes in carbon dioxide and carbon monoixide.
Alkaline Earth Metals and their compounds
The alkaline earth metals are six elements in column (group) 2 of the Periodic table.
They are beryllium (Be),magnesium(Mg),calcium (Ca), strontium (Sr),barium (Ba), and radium (Ra).They have very similar properties: they are all shiny, silvery-white, somewhat reactive metal at same temperature and pressure.
- Mg(OH2) is known as milk of magnesia and use as an antacid.
- It is also known as quick lime.
- Used in the manufacturing of calcium chloride, cement and bleaching powder.
Calcium sulphate (CaSO4):
The compound exists in three levels of hydration:
- anhydrous state (mineral name: “anhydrite”) with the formula CaSO4
- dihydrate (mineral name: “gypsum”) with the formula CaSO4(H2O)2.
- hemihydrate with the formula CaSO4(H2O)0.5
- It loses a part of water to form plaster of Paris.
- Plaster of Paris is a white powder which becomes hard on contact with water and is used in the manufacturing of statues.
Some Important Metals & Their Uses
- Ore of aluminium is bauxite.
- It is the third most abundant element in the earth’s crust.
- Used in the manufacturing of cooking utensils.
- Ammonal , a mixture of aluminium powder and ammonium nitrate is used as an explosive.
- The ore of tin is Cassiterite.
- The process of converting white tin to grey tin is known as tin disease or tin plague.
- Used in plating of iron to protect the iron from rusting.
- Tin amalgam is used in the manufacturing of mirrors.
- Main ore of lead is galena.
- Use in the preparation of sulphuric acid through chamber process.
- Lead acetate is known as sugar of lead.
- It is used in the galvanisation process to prevent the rusting of iron.
- Zinc sulphide is used in the preparation of X-ray screens.
- Zinc oxide is known as philosopher wool.
- It is the only metal which is liquid at room temperature.
- It forms alloys with all other metal except iron and platinum.
- Silvery white soft metal.
- Used as anode in Edison batteries.
- Extracted from the haematite ore and do not occur in Free State due to its reactivity.
- Ferric chloride is used as stypic to stop bleeding from the cut.
- Ferrous sulphate is used in making blue black ink.
- It is an alloy of iron, chromium and nickel.
- Used in making automobiles parts and utensils
important Notes on Non-Metals and Metalloids
In this article we will discuss about the Non-Metals and Metalloids. One liner type question usually comes from this topic. Every year there is a question from this topic in SSC Exam.
- Non-metal may be solid, liquid or gas.
- Bromine is the only liquid non metals.
- Non metals are the elements that do not have the properties of the metals.
- They are soft, non lustrous, brittle ,non sonorous and poor conductor of heat and electricity .e.g. carbon, hydrogen, helium, neon krypton etc.
Important Non metals
- Carbon belongs to the group 14 of the periodic table.
- Carbon occurs both in free state as well as in combined state.
- Carbon has two crystalline allotropes diamond and graphite.
Allotropes of Carbon:
- Diamond is the hardest substance and is the bad conductor of electricity.
- Diamond is the purest form of the Carbon
- Used in making of jewellery and cutting glass.
- Its an exception , it is a good conductor of heat and electricity.
- Used in nuclear reactor as a moderator.
Compounds of Carbon:
- It is colourless, odourless, neutral and highly poisonous gas in nature.
- Combines with haemoglobin to form Carboxyhaemoglobin, which is not able to absorb oxygen as result leads to suffocation
- Wood fire or coal fire in a closed room leads to the formation of the carbon monoxide which leads to the death of the persons in the rooms.
- Occur in the air to the extent of 0.03-0.05 percent.
- Solid CO2 is known as dry ice.
- Dry ice is used is used in transport of perishable food material as it provides cold and inert atmosphere which helps in killing bacteria, fungi, modules etc.
- Carbon dioxide is used by the plants in the process of photosynthesis for the formation of oxygen.
- Carbides are the compound of carbon with metals or electro-negative elements.
- Silicon occurs in nature in the form of sand but never found in free state.
- This is a non-metallic element which also exhibits the characteristic of allotropy.
- This is the second most abundant element on the earth crust after oxygen
- Used as a superconductor in making computer chips.
- Silicon carbide is an artificial diamond called carborendum.
- Silica is also called sand which exist most abundantly in solid state in the nature and used in the production of glass, cement etc.
- Quartz is a crystalline form of SiO2.
- Important constituent of air about 79% by volume.
- Used in the manufacturing of nitric acid, ammonia and other nitrogen compounds.
- As a refrigerant in liquid form.
- To provide inert atmosphere in different metallurgical operation.
- Used as preservative in the food packing.
Compounds of Nitrogen:
- Most important compound of nitrogen.
- Prepared by Haber’s process.
- It is soluble in water and its aqueous solution is alkaline in nature.
- Used in refrigerator and manufacturing of fertilisers and explosives.
- Nitrous oxide(N2O) is used as laughing gas .
- The symbiotic bacteria present in the root nodules of leguminous plant convert the atmospheric nitrogen into compounds of nitrogen .e.g. Azobactor.
- It is highly reactive non metal that why it does not occursinfree state.
- Phosphorus is an essential constituents of bones, teeth, blood nerves and tissue.
- Bones contains 80% phosphorus.
Allotropes of phosphorus:
- White phosphorus:
- Red phosphorus
- Black phosphorus
- Scarlet phosphorus
- Violet phosphorus
- Oxygen exist in two allotropic form that is in most stable diatomic form(O2) and in less stable triatomic form (O3) ozone.
- Oxygen is the supporter of combustion but it is non-inflammable.
- Oxygen dissolved in blood in the form of oxyhaemoglobin.
- Liquid oxygen mixed with freshly divided carbon is used in place of dynamite in coal mining.
- Ozone is formed by the action of UV rays from the Sun on Oxygen and protects the living beings by not allowing UV rays to reach the earth.
- Ozone is also used as germicide and disinfectant for sterilizing water and for detecting position of double bond in unsaturated organic compounds.
- Sulphur occurs in free state in volcanic areas.
- Suphur exists in five allotropic form.
- Sulphur is used in rubber industry for vulcanization of rubber.
- Sulphuric acid is also known as oil of vitrol or king of chemicals.
- Sulphuric acid is prepared by two process i.e. lead chamber process and contact process.
- Halogens are highly reactive elements and therefore they do not exist in free state but exist only in combined form.
- Halogens have highest electron affinity so they act as strong oxidising agent.
- Their oxidising power decreases from fluorine to iodine.
- Chlorine always present in combined state in nature in the form of chlorides .
- Chlorine was first discovered by Scheele by the action of hydrogen chloride on manganese dioxide.
- Chlorine is used as an bleaching agent.
- Reacts with water to form HCL and HCIO.
- Used as disinfectant and oxidising agent ,
- It is used as an antiseptic as tincture of Iodine.
- Used in the cure of Goitre.
- Turns starch solution blue.
- Helium, neon , argon, krypton , xenon and radon are known as inert gases or noble gases.
- These elements have completely filled valence shell and so these do not form chemical bonds..
- These are always found in free state but radon is not present in nature.
- In atmosphere argon is the most abundant noble gas but in universe helium is the most abundant gas.
- Mixture of Helium and Oxygen is used for artificial breathing of Asthama patients and by sea drivers.
- Helium is used as pressuring agent in rockets to expel liquid oxygen and liquid hydrogen.
- Neon is used in neon discharge lamp and signs for advertising purposes.
- Xenon is also known as stranger gas and combined mixture of xenon and krypton is used in high intensity photographic flash tubes.
- Radon is used in the preparation of ointment for the treatment of cancer.
- A mixture of argon and nitrogen is used in electric bulb.
- Krypton is used in high efficiency miner’s cap lamps.
- They have properties of both metals and non-metals.
- Six commonly known metalloids are boron, silicon, germanium, arsenic, antimony and tellurium.
- Typical metalloids have a metallic appearance but they are brittle and only fair conductor of electricity.
- Metalloids and their compounds are used in the manufacturing of alloys , biological agents, flames retarders, glasses, optical storage
Chemistry Notes on Synthetic Material and Chemical Used in Everday life
In this article we will discuss about some synthetic material and chemicals that are used in everyday life e.g. cement, dye, and fertilizer. This topic is important as per competitive exam perspective.
Material created by man using the natural materials is known as the synthetic materials. Some important synthetic materials are given below:
- Discovered by English Mason, Joseph Aspdin, he named it Portland cement.
- Limestone, clay and gypsum are some important raw material that is required in the manufacturing of the cement.
- When cement is mixed with water and left for some time, it becomes a hard mass. This is known as setting of Cement, it is an exothermic process that’s why sprinkling of water is done for few days for a new construction.
- Mortar is a mixture of cement, sand and water; it is used for plastering walls and binding bricks.
- Concrete is a mixture of cement, sand, gravel and water. It is used for the construction of floors.
- Structure having iron rods embedded in wet concrete is known as reinforced concrete.
- It is a super cooled liquid of silicate, it is amorphous in nature.
- Raw material used for the formation of glass is sodium carbonate, calcium carbonate and sand.
- Sudden cooling of molten glass make it brittle if cooled very slowly make it opaque.
- The process of slow and uniform cooling is called annealing.
- When glass is attacked by hydrofluoric acid, it is called etching of glass.
- Coloured glass is obtained by adding certain metallic oxides or salts to the molten glass.
Types of glasses and their uses
Soft glass (Soda Glass):
- Mixture of sodium or calcium silicate.
- Used in making of glass, mirrors and common glass ware etc.
- Mixture of potassium and calcium silicates.
- Resistant to the action of acids and used for making hard glass.
Pyrex glass ( Borosilicate glass) :
- Used by fusing a mixture of sand, lime, borax and alkali carbonates.
- Used in making of pharmaceuticals containers.
- Glass wool is an excellent heat insulator.
- Used in insulating material in oven, refrigerator.
Chemicals Used in Agriculture:
- These are the chemical substances which are rich in a particular nutrient.
- They supply nitrogen phosphorus and potassium.
- Excess used of fertilisers can reduce the fertility of soil.
- Good fertilisers are easily dissolved in water and stable so that elements are retained for longer duration.
- It should not disturb the pH level of the soil.
- Urea is the best fertilisers.
- Calcium superphosphate, nitro phosphate, triple phosphate and phosphatic slag(Thomas slag) are some important phosphatic fertilisers.
- Mixture of nitrogenous, phosphatic and potash fertilisers in proper ration is called NPK fertilisers.
- NP fertilisers are prepared by mixing nitrogenous and phosphatic fertilisers in a definite ratio.
Pesticides are the chemicals which are used to kill pests which adversely affect the crops e.g. DDT and malathion .They can be categorised into the following category:
- Rodenticides: Zinc phosphide is used to kill rodents.
- These are the substance which contains a great amount of stored energy that can produce an explosion.
- Chemical explosives may consist of either a chemically pure compound such as nitroglycerine or a mixture of a fuel and an oxidiser.
Types of Explosives:
- A relatively small amount of energy is required for initiation.
- Use in detonators e.g. acetone peroxide, silver azide and ammonium permanganate.
- Are less sensitive and require more energy for initiation.
- RDX and TNT are some secondary explosives.
- Used in large scale mining and construction operation and in terrorism.
- Nitro-glycerine is a highly unstable and sensitive liquid also called Noble’s Oil.
- Dynamite is a mixture of highly sensitive nitro-glycerine with saw dust, powered silica.
- RDX (Research and development explosive) is a very powerful explosive.
- Colured substances used for colouring wool, textiles materials and foodstuffs.
- A material which is used as dyes must be able to fix itself to the material it is applied and must be resist the action of water, acids and alkalies.
Dyes can be classified into the following category:
- These dyes contain the azo group (-N=N-).
- Formed during the coupling reactions, e.g. red, orange.
- These dyes contains indigoid group in their molecules e.g. indigo.
On the basis of their applications dyes can be classified into the following types:
Vat Dyes: these dyes are water insoluble dyes and applied to fibre cotton and are obtained from indigo dyes.
Direct Dyes: these dyes can be applied to the fabric from their aqueous solution.
Acid dyes: used as their sodium salts which are soluble in water.
Basic dyes:In acidic medium these dyes are used to dye modified nylons and polysters e.g. aniline yellow and malachite green.
List of Some Important Ores of Metals
Generally questions from the topic Elements and their Ores are asked in every competitive exam. So, here are short notes on Some Important Ores of Metals which will be useful for upcoming SSC as well as other competitive exams as well.
Ores – Those minerals from which the metals are extracted commercially and economically and with minimum effort are called Ores of Metals.
Aluminium, for example, is the most common metal in the Earth’s crust, occurring in all sorts of minerals. However, it isn’t economically worthwhile to extract it from most of these minerals. Instead, the usual ore of aluminium is bauxite – which contains from 50 – 70% of aluminium oxide.
Copper is much rarer, but fortunately can be found in high-grade ores (ones containing a high percentage of copper) in particular places. Because copper is a valuable metal, it is also worth extracting it from low-grade ores as well.
Let us have look on a list of some Important Elements and their Ores along with their chemical formula.
Some Important Ores of Metals
1. Name of Elements: Aluminum (Al)
Ores: Bauxite: Al2O32H2O
2. Name of Elements: Iron (Fe)
Ores: Hematite: Fe2O3
3. Name of Elements: Copper (Cu)
Ores: Copper Pyrite: CuFeS2
Copper Glance: Cu2S
4. Name of Elements: Zinc (Zn)
Ores: Zinc Blende: ZnS
5. Name of Elements: Sodium (Na)
Ores: Rock Salt: NaCl
Sodium Carbonate: Na2CO3
6. Name of Elements: Potassium (K)
Ores: Karnalite: KClMgCl6H2O
Salt Petre: KNO3
7. Name of Elements: Lead (Pb)
Ores: Galena: PbS
8. Name of Elements: Tin (Sn)
Ores: Tin Pyrites: Cu2FeSnS4
9. Name of Elements: Silver (Ag)
Ores: Silver Glance: Ag2S
10. Name of Elements: Gold (Au)
Ores: Calve rite: AuTe2
11. Name of Elements: Mercury (Hg)
Ores: Cinnabar: HgS
12. Name of Elements: Magnesium (Mg)
Ores: Dolomite: MgCO3CaCO3
Name of Elements: Calcium (Ca)
Ores: Lime Stone: CaCO3
Name of Elements: Phosphorous (P)
Ores: Phosphorite: Ca3(PO4)CaFe2
Common Names and Formulas of Important Chemical Compounds
Common Names and Formulas of Important Chemical Compounds
Chemical formulas provide a lot of information about chemical substances, such as how many and what atoms they are made of, as well as the way the atoms are arranged.
A compound is a substance made up of a definite proportion of two or more elements. A chemical formula tells us the number of atoms of each element in a compound. It contains the symbols of the atoms of the elements present in the compound, as well as how many there are for each element in the form of subscripts. Below are a few examples of a few compounds and what their chemical formulas are:
1. Common Names: Baking Powder
Chemical Compounds: Sodium Bicarbonate
Chemical Formula: NaHCO3
2. Common Names: Blue Vitriol
Chemical Compounds: Copper Sulphate
Chemical Formula: CuSO4.5H2O
3. Common Names: Bleaching Powder
Chemical Compounds: Calcium Oxychloride
Chemical Formula: CaOCL2
4. Common Names: Chloroform
Chemical Compounds: Trichloro Methane
Chemical Formula: CHCl3
5. Common Names: Chalk (Marble)
Chemical Compounds: Calcium Carbonate
Chemical Formula: CaCo3
6. Common Names: Caustic Potash
Chemical Compounds: Potassium Hydroxide
Chemical Formula: KOH
7. Common Names: Caustic Soda
Chemical Compounds: Sodium Hydroxide
Chemical Formula: NaOH
8. Common Names: Dry Ice
Chemical Compounds: Solid Carbondioxide
Chemical Formula: CO2
9. Common Names: Epsom
Chemical Compounds: Magnesium Sulphate
Chemical Formula: MgSo4
10. Common Names: Gypsum
Chemical Compounds: Calcium Sulphate
Chemical Formula: CaSo4
11. Common Names: Green Vitriol
Chemical Compounds: Ferrous Sulphate
Chemical Formula: FeSo4
12. Common Names: Heavy Water
Chemical Compounds: Deuterium Oxide
Chemical Formula: D2O
13. Common Names: Vinegar
Chemical Compounds: Acetic Acid
Chemical Formula: CH3COOH
14. Common Names: Washing Soda
Chemical Compounds: Sodium Carbonate
Chemical Formula: Na2CO3
15. Common Names: Slaked Lime
Chemical Compounds: Calcium Hydroxide
Chemical Formula: Ca(OH)2
16. Common Names: Potash Alum
Chemical Compounds: Potassium Aluminium Sulphate
Chemical Formula: KALSO4
17. Common Names: Quick Lime
Chemical Compounds: Calcium Oxide
Chemical Formula: CaO
18. Common Names: Plaster of Paris
Chemical Compounds: Calcium Sulphate
Chemical Formula: CaSO42H2O
19. Common Names: Mohr’s Salt
Chemical Compounds: Ammonium Ferrous Sulphate
Chemical Formula: FeSO4(NH4)2SO4.6H2O
20. Common Names: White Vitriol
Chemical Compounds: Zinc Sulphate
Chemical Formula: ZnSo4.7H2O
21. Common Names: Marsh Gas
Chemical Compounds: Methane
Chemical Formula: CH4
22. Common Names: Magnesia
Chemical Compounds: Magnesium Oxide
Chemical Formula: MgO
23. Common Names: Laughing Gas
Chemical Compounds: Nitrous Oxide
Chemical Formula: N2O
24. Common Names: Vermelium
Chemical Compounds: Mercuric Sulphide
Chemical Formula: HgS
25. Common Names: Sugar
Chemical Compounds: Sucrose
Chemical Formula: C12H22O11
26. Common Names: T.N.T.
Chemical Compounds: Trinitrotoluene
Chemical Formula: C7H5N3O6
27. Common Names: Sand
Chemical Compounds: Silicon Oxide
Chemical Formula: SiO2
Short Notes on Important Fuels and their Composition
- The substance, which produce heat and light on combustion are called fuels.
- A strong foul smelling substance, called ethyl mercaptan is added to LPG to detect its leakage as LPG is an odourless gas.
Some Important Fuels and their Compositions
Physical and Chemical Changes
- Physical changes are the change, which only affect the physical properties like colour, hardness, density, melting point etc. of matter, but do not affect the composition and chemical properties of matter.
- A physical change is temporary, while a chemical change is permanent.
- Crystallisation, sublimation, ‘boiling, melting, vaporisation, cutting of trees, dissolving sugar or salt in water etc. are physical changes.
- Chemical changes affect the composition as well as chemical properties of matter and result in the formation of a new substance.
- Burning of fuel, burning of candle and paper, electrolysis of water, photosynthesis, ripening of fruits etc, are examples of chemical changes
Coal is obtained by carbonization of vegetable matter and is available in different varieties:
- Peat- 60% C
- Lignite or Brown Coal – 70% C
- Bituminous – 60 to 80 % C
- Anthracite Coal – 90% C
Flame contains three parts
- Innermost Part- which is black due to the presence of unburned carbon particles- has lowest temperature.
- Middle part – is yellow due to incomplete combustion of fuel.
- Outermost part- which is blue due to complete combustion of fuel is the hottest and used by goldsmith to heat the gold.
- Water extinguishes fire because as it evaporates, the vapours surround the burning substance, cutting off the oxygen supply, thus inhibiting burning process.
- In case of electrical or oil (petrol) fires, water cannot be used as extinguisher. This is because water is a conductor of electricity and heavier than oil. Thus, oil floats over it and continues to burn.
- Carbon dioxide, which is generated by the reaction of baking soda with acid, is used extinguish electrical or oil fires. Quality of petrol is measured in terms of octane number and that of diesel in terms of cetane number.
In safety matches, the stick consists of mixture of antimony trisulphide and potassium chlorate at its one end. The box side contains a mixture of powdered glass and phosphorus.
Chemical Formula & Uses of Some Important Compounds
Here is the list of Compounds
1. Compound Name: calcium carbonate
Uses: Non-prescription drug for relief from acid indigestion and heartburn. Also considered a calcium supplement..
2. Compound Name: sodium chloride
Uses: Used to season food (during food preparation and at the table), also used in the past as a method of food preservation.
3. Compound Name: Methane
Uses: natural gas, fuel (also called Marsh Gas)
4. Compound Name: Aspirin
Uses: Pain Reliever
5. Compound Name: Potassium tartrate
Uses: cream of tartar, cooking
6. Compound Name: Baking soda
7. Compound Name: Acetaminophen
Uses: Pain Reliever
8. Compound Name: Acetic acid
Uses: Active ingredient in vinegar
9. Compound Name: Caffeine
Uses: stimulant in coffee, tea, some soda
10. Compound Name: Propane
Uses: fuel for cooking
11. Compound Name: Sodium carbonate
Uses: washing soda
12. Compound Name: Phosphoric acid
Uses: flavouring in soda
13. Compound Name: Ascorbic acid
Uses: Essential vitamin (vitamin C)
14. Compound Name: Ammonia
Uses: fertilizer, household cleaner when dissolved in water
15. Compound Name: Ethylene glycol
16. Compound Name: Calcium carbonate
17. Compound Name: Ethanol
Uses: disinfectant, alcoholic beverages
18. Compound Name: Carbon dioxide
Uses: carbonating agent in soda
19. Compound Name: Hydrochloric acid
Uses: production of batteries, photoflash bulbs and fireworks. It’s even used to process sugar and make gelatin.
20. Compound Name: calcium oxide
Uses: Less common in modern homes than in the past. Glows when heated; was used in theatres before invention of electric lighting. Health risks on skin contact or inhalation.
21. Compound Name: Sucrose
Uses: Used in cooking. Use as a sweetener.
22. Compound Name: potassium carbonate
Uses: Potash is the common name for various mined and manufactured salts that contain potassium in water-soluble form.
23. Compound Name: Plaster of Paris
Uses: used for casts to hold broken limbs in place, modelling casts, sculptures and in plasterboard walls and ceilings
24. Compound Name: Gypsum
Uses: Use to manufacture dry wall, plaster, joint compound.
25. Compound Name: sodium bicarbonate
Uses: Used in baking where it reacts with other ingredients, releasing carbon dioxide (CO2), helping dough rise.
26. Compound Name: sulphuric acid
Uses: Used in lead-acid batteries for cars and other vehicles. Formerly it was known as vitriol.
27. Compound Name: hydrogen peroxide
Uses: Used as a mouth wash (Personal Hygiene)
Chemistry Notes : Mixture and its separation Method
Mixture: A mixture is a substance that constitutes two or more element or compound, chemically combined together in any ratio. It can be separated into its constituent element by physical methods. It has variable melting and boiling point and the properties shown by the mixture are depend on its constituent element.
Types of Mixture
Heterogeneous Mixture: A mixture in which the constituent elements are distinctly visible, and do not show the properties of its constituent element. Normally the colloidal solution are heterogeneous in nature i.e. mixture of salt and sugar, suspensions etc.
Homogeneous Mixture: A mixture in which the constituent element are uniformly distributed throughout the mixture and show the properties which are similar to the constituent element i.e. the electrolyte of sulphur in carbon dioxide.
Process used for the separation of its constituent element
Here are some methods used for the separation of mixture. The selection process depends upon the nature of the constituent element.
It is used for the separation of the insoluble solid component of the mixture from the soluble component in a given solvent, e.g. in car engines solid particles from engine oil are separated by air filters, for separation of naphthalene and urea.
This method is used to purify the solids, on the basis of heating. In which the pure component is left behind, e.g. for obtaining salt from the sea water.
This is used to separate the volatile component from the non-volatile component. In this process the soluble solid solute dissolved in the solvent is obtained generally by heating the mixture, e.g. for manufacturing the ink.
Centrifugation: This process is used for the separation of the insoluble particles from the liquid where normal filtration process does not work. This process normally depends on the particles size, density and viscosity. The principle is that the denser particles are forced to the bottom and the lighter particles stay at the top when rotate rapidly, e.g. separation of cream from the milk.
Sublimation: It is used to separate sublimate volatile substances such as ammonium chloride from the non-sublimate substances such as sodium chloride. Sublimate substances are iodine, naphthalene, camphor.
Distillation: Liquid having sufficient difference in their boiling point are separated through this process. Used for the preparation of distilled water from the normal ordinary water.
It is used when there is a small difference in the boiling point of the liquids. This process is mainly used in industrial process, e.g. refining of the crude oil and manufacturing of the alcoholic beverages such as whisky and rum.
Differential Extraction: It is used for the organic compound present in the water by using another immiscible liquid in which organic compounds are more soluble, e.g. iodine in water is extracted by using chloroform.
Chromatography: It is used to separate mixture into its constituent component to purify compounds and also for testing the purity of the compounds. Pigments from natural clours and drugs from blood are separation by this technique.
Chemistry Notes on Acids and Base
Acids which are obtained from plants and animals are called organic acid e.g. lactic acid, oxalic acid, acetic acid.
Acids which are obtained from minerals are called mineral acids, e.g. sulphuric acid and phosphoric acid.
Arrhenius concept of acids and bases:
- Acids is a substance which produces hydrogen ions in aqueous solution e.g. HCL, sulphuric acid.
- Base is a substance which produces Hydroxide ion (OH–) in aqueous solution e.g. sodium hydroxide and ammonium hydroxide etc.
Bronsted Lowery concept of Acids and Bases
- An acid is a molecule or ion which is capable of donating a proton.
- A base is a molecule or ion which is capable of accepting a proton.
Lewis concept of Acids and Bases
- An acid is a substance which can accept an electron e.g. boron fluoride (BF3) and carbon dioxide.
- Base is a substance which can produce an electron e.g. fluoride (F–) and chloride (Cl–).
Some important acids and their presence
- PH value is a measure of the acidity or basicity of an aqueous solution.
- Solution with PH value less than 7 is considered as acidic.
- Solution with PH value greater than 7 is greater 7 is considered as basic.
PH values of some important solutions.
- The solutions which resists the change in its PH value on addition of a small amount of acid or base are called buffer solutions.
- Acidic buffer solution has PH value less than 7.
- Basic buffer has PH value greater than 7.
- PH value of blood is maintained with the help of H2CO3/HCO3 buffer inspite of many acidic foods we eat.
- When acidic and basic solutions are mixed in proper proportion than their own nature is destroyed and Salt is formed.
- Acid turns blue litmus red and base turns red litmus blue.
- Formation of salts after mixing base and acidic is called as neutralisation reaction.
Chemistry Notes on Polymers & Chemical used in Medicine.
- Polymers are large complex molecule that are made of some small repeating unit known as monomers.
- Monomers are the building block of polymers.
- Polymers can be natural and synthetic depends on its origin, e.g. Cellulose is a natural polymers and polythene is a synthetic or man made polymers.
- The process of formation of polymers from respective monomers is known as polymerization.
Some important polymers are as follows:
Polythene: Monomers of polythene is ethylene and it is used in the manufacturing of packaging material ,carry bags and bottles.
Polypropene: Its monomers is propylene and it is used in the manufacturing of bottles and crates.
Nylon(Polyester): Monomer of Nylon is caprolactam and this is used in the manufacturing of fibers and ropes.
Polyvinyl chloride(PVC): Monomers of polyvinyl chloride is vinyl chloride and it is used in the manufacturing of pipes and insulation.
Teflon: Tetrafluroethylene is used as monomers in preparation of Teflon. Teflon is used in the preparation of nonstick kitchen ware.
Bakelite: Its monomer is phenol formaldehyde and it is used in the preparation of electrical insulation.
Natural rubber: Its monomer is isoprene.
Lexan: It is used in the preparation of bullet proof glass.
Melamine: It is used in the preparation of crockery.
- Soap is a sodium salt or potassium salt of long chain fatty acids having cleansing action in water.
- They are using as cleansing agents to remove dirt, oil from the skin and clothes.
- Generally soaps are prepared by heating animal fat or oil with alkalies like sodium hydroxide or potassium hydroxide,this reaction is known as saponification reaction.
- Glycerol is by -product formed in the saponification reaction and it is used in the preparation of cosmetics, paints and even explosives.
- The cleaning action of soap is due to micelle formation and emulsion formation.
- Detergents have almost the same properties as soaps but they are more effective in hard water.
- Detergents are generally ammonium or sulphonate salts of long chain carboxylic acids.
- The charged ends of these compounds do not form insoluble precipitates with the calcium and magnesium ions in water.
Various types medicine:
Analgesics: Painkillers are called analgesics e.g. Aspirin, paracetamol and morphine. Acetyl salicylic acid is used in the preparation of aspirin.
Antimalarial Drugs: These drugs are used to treat malaria.
Suphadrugs: Alternatives of antibiotics, sulphanilamide, sulphadiazine, sulpha gunamidine.
Antaoxide: Substance which remove the excess acid and raise the pH to appropriate level in scotch are called antacids. It is caused by excess of HCL in the gastric juice magnesium hydrate . Aluminium phophene are common antacids.
Epsom salt: Hydrated magnesium sulphaate used in medicines to empty bowels.
Chlorofrom: A sweedish, colourless liquid and it is used as anaesthetic.
Saccharin: It i s used by Diabitic patients in place of sugar.
DDT: It is used as an insecticide.
- Atoms, molecule or ions or different elements except the noble, do not have complete or stable octet so they combine with other element to completer its octet, this process of completing its octet by combining with other element is known as chemical bonding.
- Valency is the main point on which chemical bonding depends.
- Valency of an element is the capacity to form chemical bonds and it is equal to the number of electron in its atom.
- An ion is electrically charged particle.
- A positively charged particle is called cation while a negatively charged particle is known as anion.
- A cation is formed due to the loss of electron (Na+, H+).
- An anion is formed due to the gain of electron (F–, Cl–).
Types of chemical bonding:
Chemical bonding are of following types depending upon the sharing of electron or transfer of electron.
- Electrovalent Bond:
- The bond formed by the transfer of electron from one atom to another is called electrovalent bond or ionic bond.
- The compound formed due to electrovalent bond is called electrovalent compound or ionic compound.
- These bonds are formed between metals and non-metals.
- Electrovalent compound have high melting and boiling point.
- They are conductor of electricity when dissolved in water.
- They are soluble in water but no in organic solvents like alcohol.
- e.g. Aluminium Oxide (Al2O3), Ammonium chloride (NH4Cl) and Calcium chloride (CaCl2)
- The bond is formed by the sharing of electron between two atoms of the same or different elements, is called covalent bond and the compound formed due to this bonding is called Covalent compound.
- Covalent bond may be single, double or triple depending upon the number of sharing pairs of electron.
- Covalent compounds have low melting and boiling point.
- They do not conduct electricity and are insoluble in water but dissolve in organic compound.
- e.g. Alcohol (C2H5OH), Ammonia (NH3), Ethane (C2H6), Methane (CH4).
Coordinate and Dative Bond:
- The bond is formed by one sided sharing of one pair of electrons between two atoms.
- The main condition for formation of Coordinate bond is that octet of one atom should be complete , having atleast one lone pair of electron and other atom should have a deficiency of atleast one pair of electrons.
- The atom having complete octet which provides the electron pair for sharing is known as donor.
- The other atom which accepts the electron pair is called acceptor.
- A bond is formed by the linear overlapping of atomic orbitals is called sigma bond.
- The extent of overlapping in sigma bond is large so they are strong bond.
- This bond is formed by the lateral or sidewise overlapping or atomic orbitals.
- Since the extent of overlapping is small so they are weak bond.
- e.g. in O2 one bond is sigma and one is pi bond.
When hydrogen atom is present between two most electronegative atoms then it is bonded to one by a covalent bond and to other by a weak force of attraction which is called hydrogen bond.
e.g. Present in H2O and HF.
Chemistry Notes on Atomic Models and Quantum numbers
To show the arrangement of fundamental particles in an atom various models were proposed, some important models are as follows:
Dalton’s Atomic Theory:
The different assumptions of this theory are as follows;
- All matters are made up of atoms which are indivisible and indestructible.
- All the atoms of a given element have identical properties including identical mass.
- Atoms combine in small whole numbers to form compound
- Chemical reactions involve only combination, separation or rearrangement of atoms.
Thomson’s Atomic Model:
- Every atom consist of uniformly positively charge sphere having radius in the order of 10-10 m in which entire mass is uniformly distributed and negatively charges electrons are embedded randomly.
- Thomson uses the cathode ray tube to gives its atomic model.
- This model is known as plum pudding model.
- According to him negative charge particles are distributed in atom and to balance this negative charge some positive charge particles also present in it.
- The atom as a whole is neutral.
Drawbacks of Thomson’s Atomic Model:
- It could not explain the origin of spectral series of hydrogen and other atoms.
- It could not explain large angle scattering of alpha particles.
Rutherford’s Atomic Model:
- He fired a beam of alpha particle on a sheet of gold to gives its model theory.
- The existence of nucleus was proved by Rutherford in his alpha particle scattering experiment.
- The entire positive charge and almost entire mass of atom is concentrated at its centre in a very tiny region of the order of 10-15m, called nucleus.
- The negatively charged electrons revolve around the nucleus in different orbits.
- Total positive charge on nucleus is equal to the total negative charge on electron; therefore atom as overall is neutral.
- A nucleus consists of positively charged protons and electrically neutral neutrons.
Limitations of Rutherford’s Atomic models:
- According to Maxwell electromagnetic wave theory an accelerated charged particles emits its energy in the form of electromagnetic waves. Therefore an electron must emit emits energy during its course of accelerated motion around the nucleus. Due to which the radius of its path will decrease gradually and ultimately it will fall in the nucleus.
Plank’s Quantum Theory:
Planck gave a new revolutionary theory of radiation known as quantum theory of radiation.
According to this theory
Radiant energy is not emitted or absorbed continuously but discontinuously in the form of small packets of energy known as photons (quanta).
The amount of energy associated with a quantum of radiation is proportional to the frequency of radiation.
Where h is Planck’s constant
- Bohr’s model is based on the quantum physics i.e. quantization of energy
- This model is similar to planetary model in which electron revolves around the nucleus in specific orbit
- Bohr’s model is considered as the primitive hydrogen atom model
- Every orbit has a specific size and energy level.
- Smallest energy is found in the smallest orbit as energy is related to the size of the orbit.
- Electrons can move from one orbit to another by emitting or absorbing energies according to quantum mechanisms.
Heisenberg’s Uncertainty Principle:
- According to this theory the position and velocity or momentum cannot be measured at a single instant.
- Heisenberg principle is not applicable to macroscopic objects
- De Broglie states that electron have dual nature i.e. wave nature and particle nature
- Wavelength (l) of an electron is inversely proportional to its momentum (p)
l=h/p=h/mv, here h is Planck’s constant
The electron has a definite energy characteristic of the orbit in which it is moving. These orbit or energy levels or shells therefore also known as stationary orbits.
The shell with n=1 is closest to the nucleus and an electron in this level has the lowest energy as it is closest to the positive charge of the nucleus.
Distribution of electrons in different orbits:
- It was suggested by Bohr and Burry and rules that govern it are as follows:
- The maximum number of electrons present in a shell is given by the formula 2n2 where n=1,2,3 and 4 for K,L,M and N shells respectively.
- The maximum number of electrons that can be accommodated in the outermost orbit is 8.
- The shells are filled in a step-wise manner.
- It is the arrangement of electrons in various shells, sub-shells and orbitals in an atom.
- It is written as 2,8,8,18,32
- The maximum number of electron in a shell is given by 2n2
Filling or orbitals in Atoms:
The filling of electrons into orbitals of different atoms takes place according to the Aufbau Principle, Pauli Exclusion Principle and Hund’s rule of maximum multiplicity.
According to Aufbau principle in the ground state of an atom, electron enters the orbital of lowest energy first and subsequent electrons enter in the order of increasing energies.
Lower the value of (n+l) for an orbital, lower is its energy.
here l is the azimuthal quantum number and n indicates the principle quantum number
If two orbitals which have same (n+l) value, the orbital with lower value of n has lower energy.
Hund’s rule of maximum multiplicity deals with the filling of electrons into the orbitals belonging to the same sub-shell. According to this rule, electron pairing will not take place in orbital of same energy until each orbital is first singly filled with parallel spin.
Each electron in an atom is characterised by a set of definite values of three quantum numbers n, l and m. In addition of these three numbers, fourth quantum numbers is also needed which specifies the spin of the electron.
Principal quantum number (n):
Determines the main energy level of shell in which the electron is present.
The various values of n are 1, 2, 3 and 4 etc. also known as K, L, M and N etc. respectively, as the value of n increases energy of electron also increases.
Azimuthal quantum number (l) determines the sub-level or sub-shell(s, p, d and f) in a given principal energy level or shell to which an electron belongs.
Magnetic quantum number (m) gives the information about the orientation of the orbitals.
Spin quantum number(s) describe the spin orientation of the electron; the electron can spin only in two ways, i.e. clockwise or anticlockwise.
Pauli Exclusion Principle:
It states that no two electrons in an atom can have the same set of four quantum numbers.
Hydrogen Derivatives of Hydrocarbons
- It is colourless and used as a local anaesthetic and in organic synthesis.
- Discovered by Leibig, used as the anaesthetic in surgery.
- Always stored in the dark coloured bottle as it get oxidised with the sunlight and form a poisonous gas known as Phosgene.
- It reacts with concentrated HNO3 to form Chloropicrin, a poisonous gas used in the war.
Carbon tetrachloride (CCL4):
- Used as an fire extinguisher, used as an solvent for the fats, oils in the industry.
- The chlorofluorocarbon compounds of methane and ethane are collectively known as Freon.
- They are produced by the refrigerator, A.C and propellants.
- They causes the depletion of Ozone.
Dichloro diphenyl trichloro ethane ( DDT):
- Discovered by Paul Muller and it is used as an insecticide, widely used against the mosquito and lice.
- It is highly stable and is not decomposed easily in the environment that why it is banned in several country.
- Used as insecticide, germicide and in deodorant and moth repellent.
Perfluro carbons (PFC):
- Used as an electric insulator, lubricants, dielectric, heat transfer media in high voltage.
Methyl alcohol (CH3OH):
- known as wood spirit or wood naptha.
- Used for the denaturing of alcohol (methylatd spirit is denatured ethyl alcohol).
- Used as alcohol-petrol fuel, automobile antifreeze mixtures and in the manufacturing of drugs, dyes and perfumes etc.
Ethyl alcohols (C2H5OH):
- Known as alcohol, spirit of wine or grain alcohol.
- Used as solvent in paint industry.
- Used as a antifreeze in automobile radiator and as a cooling agent in aeroplanes instead of water.
- Its dinitrate is used as an explosive with trinitroglycerine.
- Present in almost all the animal and vegetable oil and fats as glycerides.
- It is hygroscopic in nature and used in the manufacturing of the cosmetic and transparent soaps, as a lubricant for watches and clocks.
- Commonly known as carbolic acid or benzenol and prepared by the middle oil fraction of Coal Tar.
- Used in the preparation of drugs such as salol, aspirin, salicylic acid and phenacetin.
- Its 40% dilute solution is known as formalin, used as insecticide, germicide and preservative for biological specimen.
- Used in leather industry for tanning and in manufacturing of synthetic dyes and Bakelite.
- Used in the silvering of mirror and in the manufacturing of paraldehyde and metaldehyde.
- Chloral or Trichloro acetaldehyde
- Used as an sleep producing drugs and as a powerful stimulant
Acrolein or Acraldehyde
- Used in tear gas and as warming agent to find out leakage if any of methyl chloride.
Acetone or Dimethyl ketone (CH3COCH3)
- It is the fist member of keton series
- . It Is one of the constituent of the nail polish.
- Chloretone used as a medicine is obtained by the reaction of acetone with chlorofoem in the presence of potassium hydroxide.
Formic acid (HCOOH)
- Found in red ants, in the strings of bees and wasps.
- It is corrosive and produces blisters on the skin.
- Used in the preparation of fruits and as a medicine for the treatment of the Gout.
- Dilute acetic acid is used as vinegar and concentrated acid is used as solvent.
- Prepared by the fermentation process
- It is used to remove ink stains from the cloth.
- Its salt potassium ferrous oxalate is used in the photography.
- It occurs in rhubarb, sorrel and other plant of oxalic acid group in the form of potassium salts.
- It is a monohydroxy acid, present in milk
- When we do vigorous physical activity lactic acid is produced which causes pain in muscles.
- It occurs in grapes, tamarind and berries.
- Used in in dyeing industry and making baking powders.
- Rochelle salt(sodium potassium tartrate) is used in the preparation of Fehling solution.
- In Free states it is found in citrus fruit such as lemon, lime, orange and galgal.
- Used in making beverages and as a mordant in dying and calico –printing.
- It is poisonous and has antiseptic property.
- Used in the azo dyes and aspirin preparation
- It is a colourless liquid, on decomposition it gives acetone and CO2.
- It occurs in excess in urine of diabetic patients.
- It is a pale yellow oily liquid with a strong smell of bitter almonds.
- It is also known as oil of mirbane.
- Used in the preparation of aniline, benzidine, 1, 3, 5-trinitro benzene and azodyes.
1, 3, 5-trinitrobenzene or TNB
- It has greater explosive power than TNT and is used in making explosives.
- It is a pale yellow crystalline solid prepared by nitrating toluene with fluming nitric acid and fuming sulphuric acid mixture.
- Used as an explosive in bombs, shells and torpedo.
- It is an important source of energy since earlier time. In India and other country also coal is used to generate electricity.
- Coal formed beneath the earth surface by the slow decomposition of plant for a longer period.
- It is type of fossils fuel.
There are four types of coal:
On heating coal at a temperature in the range of 1270-1675 in the absence of air, it decomposed to give the following products.
- Coke: It is the solid residue left after the distillation of coal; it is used as a fuel and as a reducing agent in different metallurgical process.
- Coal Tar: It is a thick black colour viscous liquid. It is used in various industries such as dying and drugs and mainly used in the metalling of road. Now a day’s bitumen a petroleum product is used in the metalling of road.
- Fractional distillation of Coal Tar produces the following products: light oil, middle oil or carbolic oil, heavy oil or creosote oil, green oil or anthracene oil and pith.
Petroleum (Petra means rock and oleum means oil) is a fossil fuel.
It is formed under beneath the earth surface by the decomposition of dead remains of organism living in the sea.
Over the year these dead remains converts into the petroleum and natural gas due to the absence of air, high temperature and high pressure.
World first oil well was drilled in Pennsylvania (USA) in 1859 and second in India in 1867 at Makum in Assam.
Refining of petroleum is carried out in refinery.
Knocking is a metallic sound produced in engine due to low quality of petrol. Knocking can be reduce by adding antiknock compound.
TetraethylLead (TEL) and Benzene-Toluene-Xylene(BTX) are common antiknock compounds. TEL creates pollution, so its use has been stopped in India.
The antiknocking property of petrol is measured in terms of octane number. Higher the octane number, better is the quality of fuel. Gasoline used in automobiles has an octane number 80 or higher while in aeroplane, it has an octane number 100 or over higher.
The fuel used in rockets is called rocket propellant. It is a combination of an oxidiser and a fuel which on combination releases large quantities of hot gas. Propellants are of following types:
Liquid propellants: They are alcohol, liquid hydrogen, liquid ammonia, kerosene oil, nitromethane and hydrogen peroxide.
Solid propellants: Example of solid propellants are polybutadiene and acrylic acid used along with oxidiser such as aluminium per chlorate, nitrate or chlorate.
Hybrid propellant: They consists of a solid fuel and liquid oxidisers.