What is the uses of chlorine?

• Chlorine is used for producing safe drinking water and treat swimming pool water. Chlorine kills bacteria – it is a disinfectant.  
• It is also used to make hundreds of consumer products from paper to paints, and from textiles to insecticides. 
•  About 20% of chlorine produced is used to make PVC. This is a very versatile plastic used in window frames, car interiors, electrical wiring insulation, water pipes, blood bags and vinyl flooring. 
•  Another major use for chlorine is in organic chemistry. It is used as an oxidising agent and in substitution reactions.  
• Chlorine is also used for the manufacture of chlorates and it is important in organic chemistry, forming compounds such as chloroform, carbon tetrachloride, polyvinyl chloride, and synthetic rubber. 

What is the uses of fluorine?

• Fluorine is a highly reactive element that is used in processing nuclear fuel, in producing plastics and as a glass etching solution.   
• It can also be found in toothpaste and drinking water, which help prevent dental cavities and it is a component in air conditioning and refrigeration.  
• Because of its highly explosive nature, it is also used in rocket fuels. 
• Fluorine is used to refine uranium, which is used in nuclear reactors. 
• Fluorine is a component of chlorofluorocarbons. Chlorofluorocarbons were used as refrigerants in air conditioning units and freezers until they were banned because of their contribution to ozone depletion. 
• Fluorochemicals, including many high-temperature plastics such as Teflon, are also made using fluorine. 
• Hydrofluoric acid can dissolve glass and is used to etch the glass in light bulbs and in other products. 

What are the important of hydrogen in life?

• The largest use of hydrogen in the world is in ammonia manufacture. 
• The major application of hydrogen is in the catalytic hydrogenation of organic compounds. Unsaturated vegetable and animal oils and fats are hydrogenated to make margarine and vegetable shortening. 
• Hydrogen is used to reduce aldehydes, fatty acids, and esters to the corresponding alcohols. 
• Hydrogen is important because it is involved in the process of enzyme catalysis and because it stabilizes things like nucleic acids and proteins.  
• Hydrogen is important because it offers Earth another fuel source and may free the Earth from using fossil fuels someday.  
• It is currently used as a gas and liquid for many different industries and is often used to provide electricity in the fuel cells of automobiles or in internal combustion engines. For example, NASA used hydrogen to power the space shuttles. 
• Hydrogen has been used as a primary rocket fuel for combustion with oxygen or fluorine and is favoured as a propellant for nuclear-powered rockets and space vehicles. 
• Liquid hydrogen is used in the laboratory to produce low temperatures. 
• Hydrogen is important because it offers Earth another fuel source and may free the Earth from using fossil fuels someday.  

What is the difference Between Molarity and Normality?

Molarity is the number of moles of solute per liter of solution (common measurement of chemical concentration), while normality is the measure of concentration equal to the gram equivalent weight per liter of solution. Normality and molarity are both measures of concentration in chemical solutions. 

For example,  

A 1 M solution of H2SO4 contains 1 mole of H2SO4 per liter of solution. H2SO4 dissociates into H+ and SO4- ions in water. For every mole of H2SO4 that dissociates in solution, 2 moles of H+ and 1 mole of SO4- ions are formed. This is where normality is generally used. 

A 1 M H2SO4 solution will have a normality (N) of 2 N because 2 moles of H+ ions are present per liter of solution. 

N = M*n 

where n is the number of equivalents 

What is the common uses of methane?

• Methane is the main component of natural gas.  It’s a common fabric, plastic, anti-freeze and fertilizer ingredient.  
• Some consumers use the methane in natural gas as a source of energy while cooking. Others use it to heat and cool their homes. 
• Through a process called distributed generation, the methane in natural gas can create electricity.  
• Methane reacts at high temperatures with steam to yield the hydrogen used in the manufacturing of explosives and ammonia-based fertilizers. 
• Chemical reactions with this compound also yield carbon tetrachloride, methanol, chloroform and carbon black. Carbon black is used in the rubber of tires as a reinforcing agent. Chloroform is utilized in applications such as coolant and spot remover. Carbon tetrachloride is the active ingredient in fire extinguishers. 
• Other valuable chemicals derived from methane include methanol, chloroform, carbon tetrachloride, and nitromethane. The incomplete combustion of methane yields carbon black, which is widely used as a reinforcing agent in rubber used for automobile tires. 

What is the uses of argon?

• Argon is widely used as an inert gas to create an oxygen- and nitrogen-free environment for various heat-treating processes.  
• It is used for metal production, welding and metallurgy, lighting and in the automotive industry. 
• Argon is used for filling fluorescent and incandescent light bulbs. Argon does not react with the filament and prevents oxygen from corroding it.  
• In the welding and metal fabrication industry, argon is used to create an inert atmosphere between the surrounding air and liquid metal. The gas also prevents oxidation risks and minimizes smoke emissions. 
• Argon is used in the automotive industry to weld mufflers, frames and other auto parts. It also creates a nitrogen- and oxygen-free environment for the annealing process and is an important component of airbags. The tires of some luxury vehicles contain argon to reduce road noise and protect the rubber.  
• In metal production, argon is used to create a non-reactive blanket during the manufacture of titanium and other reactive elements and as a protective environment for growing germanium and silicon crystals. 

What is the important of ammonia in our life?

• Ammonia is important because it is a vital source of nitrogen to support plant life. It is also used industrially to make dyes, plastic, explosives, drugs, nitric acid and ammonium hydroxide.  
• Diluted ammonium hydroxide is used as a household cleaner. 
• Plants use the nitrogen in ammonia to produce necessary proteins.  
• Urea, ammonium sulfate, ammonium nitrate, ammonium phosphate and pure ammonia are all used as commercial fertilizers for nitrogen-poor soil. Ammonium nitrate is also a component of explosives, ammonium phosphate is used in flame-retardant wood treatments and ammonium sulfate is present in chemicals used to tan leather. 
• Ammonium salts are used in dry-cell batteries, smelling salts and water treatments.  
• Liquid ammonia is used as an industrial refrigerant. Ammonia makes an ideal refrigerant because it can absorb large amounts of heat without its temperature rising. 

What is the uses of copper in our daily lives?

• Copper is commonly used in construction, electrical wiring, plumbing and the manufacture of vehicles. It is also used to make parts for fixtures in homes. 
• Since copper is naturally antimicrobial, it is often used to make objects that are touched frequently, such as faucet handles and doorknobs. It is also highly conductive, so it is used for electrical wiring and in the construction of electronic microchips. It is soft and malleable yet strong, making it an appropriate choice for plumbing and HVAC pipes. It also corrodes very slowly in seawater and resists barnacles, so it is a good material for ship hulls. 
• Copper is mixed with zinc to form brass, and copper is mixed with tin to form bronze. Brass retains most of copper's beneficial qualities but has better acoustic properties, so it is used to make musical instruments. Aluminum bronze is commonly used in vehicle and aircraft parts. 

What is the uses of bromine in our daily lives?

• Bromine is used in everyday products such as pesticides and water treatment solutions.  
• Bromine is a reddish-brown gas that has a pungent smell and can irritate the skin, nose and eyes. 
• Bromine compounds work as soil fumigants to prevent insects from attacking plants. Most pesticide agents contain bromine because it is toxic when inhaled.  
• Flame-retardant plastics often contain bromine. Brominated flame retardants are used in televisions, computers, domestic appliances, mobile phones, furniture, upholstery and mattresses. 
• Bromine is also used to purify water, as the agent acts as a disinfectant. Bromine is often used to treat swimming pools and hot tubs. Moreover, bromine compounds control algae and bacterial population growths. 
• Photography film is developed using bromine agents, which allow the photographs to develop sufficient light levels. 
• Several over-the-counter medications and prescription drugs contain bromine compounds. For example, most antihistamines, sedatives and analgesics contain bromine. Several drugs used to treat cocaine addiction and pneumonia contain active bromine ingredients. New studies show the effectiveness of bromine-containing drugs used to treat AIDS, Alzheimer's disease and cancer. 
• The car industry is beginning to use bromine compounds for electric car batteries. The batteries are designed to produce zero emissions. 

What are SN2 reactions?

• SN2 reactions are organic chemistry reactions in which an ion called the nucleophile attacks the center of another molecule and replaces one of the ions, called the leaving groups. These types of reactions are called nucleophilic substitution reactions. SN2 reactions occur in a single step. 
• The single step for SN2 reactions occurs because the nucleophile, or incoming atom, is strong enough to essentially steal the molecular bonds from the leaving group. 
• The SN2 reaction is most commonly seen during reactions on carbon atoms that have four single bonds attached to other atoms, one of which is an electronegative, stable ion. This stable ion is frequently one of the halides, and can leave the molecule when it is forced out by the incoming nucleophile. 
• During an SN2 reaction, the incoming ion attacks from the opposite side of the carbon atom from the leaving group. The molecule undergoes a brief transition state when both the nucleophile and leaving group are partially attached to the carbon atom. This only occurs for a fraction of a second, and then the leaving group detaches from the central carbon atom, and the electron bonds transfer to the incoming ions. 

State the characteristic properties of covalent compounds

• They have usually low melting and boiling points. 
• They are usually bad conductors of electricity. 
• They are usually insoluble in water but are soluble in non-aqueous solvents like benzene, ether, alcohol and acetone.  
• Larger molecules with 3-dimensional bonding form covalent crystals which are very stable and hard. They have very high melting and boiling points.  

State the characteristic properties of ionic compounds.

• Ionic compounds are mostly crystalline solids. 
• Ionic compounds in solid state have slightly electrical conductance but they are good conductors in solution and in the molten form. It is due to presence of free ions in them.  
• Ionic compounds have high melting and boiling points. 
• They dissolve easily in polar solvents like water.   

Explain why is the BF3 electron deficient.

Boron atom has 3 electrons in its outer most shell. It forms 3 single covalent bonds with fluorine and attains 6 electrons. Boron needs still 2 more electrons to complete its octet. It accepts a lone pair through coordinate covalent bond from another molecule to complete its octet.