Never think to get admission as a first batch

Hello guys
There are lots of problems faced by the students of first batch in any college. The situation may get worst when you are in final semester and there is no campus placement. It does not matter how much intelligent you are, everything gonna be on luck. According to me ,it is better to go for a good NIT rather than a new IIT.




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Climate Change Set to Increase Ozone-Related Deaths Over Next 60 Years, Scientists Warn

A new study, which is being presented at the European Respiratory Society's Annual Congress in Amsterdam, predicts that Belgium, France, Spain and Portugal will see the biggest climate-induced increase in ozone-related deaths over the next 60 years.

The research is part of the Climate-TRAP project and its health impact assessment lead by Prof Bertil Forsberg from the Umea University in Sweden. The aim is to prepare the health sector for changing public health needs due to climate change.

According to the World Health Organization (WHO), climate change that has occurred since the 1970s caused over 140,000 excess deaths annually by the year 2004. In addition to its impact on clean air, drinking water and crop production, many deadly diseases such as malaria and those which cause diarrhea are particularly sensitive to climate change.

In this new research, the scientists used emission scenarios and models to assess the health impacts of a changing climate. They took projections from two greenhouse gas emission scenarios, A2 and A1B, and two global climate models, ECHAM4 and HADLEY, to simulate how the various future ozone levels are affected by climate change.

They compared four periods: baseline period (1961-1990); the current situation (1990-2009); nearer future (2012-2050); and further future (2041-2060).

The findings revealed that since 1961, Belgium, Ireland, The Netherlands and the UK have seen the biggest impact on ozone-related deaths due to climate change. The results predicted that the biggest increase over the next 50 yrs is likely to be seen in Belgium, France, Spain and Portugal, who could expect an increase of between 10 and 14%. However, Nordic and Baltic countries are predicted to see a decrease over the same period.

Dr Hans Orru, air pollution expert from the Umea University and University of Tartu in Estonia, explains: "Ozone is a highly oxidative pollutant, linked with hospitalisations and deaths due to problems with the respiratory system. Ground-level ozone formation is due to rise as temperatures increase with climate change. The results of our study have shown the potential effects that climate change can have on ozone levels and how this change will impact upon the health of Europeans."

Professor Marc Decramer, President of the ERS, said: "Outdoor air pollution is the biggest environmental threat in Europe. If we do not act to reduce levels of ozone and other pollutants, we will see increased hospital admissions, extra medication and millions of lost working days. As part of the European Respiratory Roadmap, which was launched last month, the ERS is calling for a collaborative approach between health professionals and policy makers, to protect vulnerable populations from the damaging effects air pollutants can have."

Important concept of carbon and compound

Carbon and Its Compounds

• The atmosphere has only 0.03% of carbon dioxide.
• The number of electrons lost or gained by an atom to complete its octet (or duplet) is called its valency. It depends on the number of valence electrons.
• The tendency to attain a completely filled outermost shell (i.e. noble gas configuration) by gaining or losing electrons is called reactivity.
• The shared pair of electrons belongs to the outer shells of both the atoms so as to attain noble gas configuration.
• The simplest molecule formed by sharing of electrons is hydrogen.
• The bonds which are formed by sharing of electrons between two atoms are known as covalent bonds.
• The compounds which are formed by sharing of electrons pair between two atoms are known as covalent compounds. E.g. CH₄, H₂, O₂, etc.
• The melting and boiling points of covalent compounds are low because their intermolecular forces are weak and less amount of energy is required to overcome these forces.
• The covalent compounds are generally poor conductors of electricity because the electrons are shared between atoms and no charged particles are formed in their solution.
• Carbon has three allotropes – graphite, diamond and Buckminster Fullerene.
• When a hydrogen atom is removed from an alkane, the group obtained is called an alkyl group.
• Saturated carbon compounds are usually not very reactive because the carbon-carbon single bonds are very strong.
• Unsaturated carbon compounds are very reactive than saturated carbon compounds.

Uses of graphite

1.     It is used in lead pencils as it is soft and leaves black mark on the paper.

2.     It, being a good conductor of electricity, is used in making electrode in the cells.

3.     Powdered graphite is used as lubricant because it is very soft and can withstand at high temperature.

Uses of diamond

1.     It is used in pencils for cutting glass etc because it is the hardest substance known.

2.     It is used for making dies for drawing thin wires.

3.     It is used in surgical tools.

4.     It is used for making jewellery because of high refractive index.

Heteroatom In hydrocarbons, the elements like halogen, oxygen, etc replacing hydrogen is called heteroatom. They are also present in some groups.

Graphite	Diamond
1.     Graphite has two dimensional structure 2.     oft and greasy. 3.     It is a good conductor of heat and electricity. 4.     It is grayish black substance.	1.     Diamond is a three dimensional structure. 2.     It is the hardest substance known. 3.     It is the bad conductor of electricity but good conductor of heat. 4.     It is transparent.

Catenation The property of self linking of carbon atoms through covalent bonds to form long chains or rings is called catenation.

• Other element which shows the catenation property is silicon.
• The bonds formed between the carbon and other elements are very strong because small size of

carbon enables the nucleus to hold on to shared-pair of electron strongly.

Versatile nature of carbon

1.     Catenation – self linking of carbon atoms to form long chains or rings.

2.     Tetravalency –sharing of 4 electrons with other atoms of carbon or any other monovalent element. 

Saturated Carbon Compounds Compounds of carbon which have only single bonds between the carbon atoms are called saturated carbon compounds.

E.g. methane, ethane, etc.

Unsaturated carbon compounds Compounds of carbon which have double or triple bonds between the carbon atoms are called unsaturated carbon compounds.

E.g. ethene, ethyne, etc.

Straight chain compounds Carbon compounds in which no carbon atom of the chain is linked to more than two other carbon atoms are called straight chain compounds.

E.g. methane, ethane, propane, etc.

Branched chain compounds Carbon compounds, in which at least one carbon atom of the chain is linked to three or four other carbon atoms are called branched chain compounds. E.g. 2-methylpropane.

Cyclic compounds Carbon compounds in which carbon atoms are arranged in a ring are called cyclic compounds. These are of two types –

1.     Saturated cyclic compounds. E.g. cyclopropane, cyclobutane, cyclopentane, etc.

2.     Unsaturated cyclic compounds. E.g. benzene.
Hydrocarbons. The carbon compounds which contain only hydrogen and carbon are called

Hydrocarbons

• Hydrocarbons which contain only single bonds between the carbon atoms are called alkanes. Their general formula is C_nH_2n+2.
• Hydrocarbons which contain one or more double bonds between the carbon atoms are called alkenes. Their general formula is CnH2n.
• Hydrocarbons which contain one or more triple bonds between the carbon atoms are called alkynes. Their general formula is C_nH_2n-2.

Functional group An atom or group of atoms present in a molecule which determines its functions or chemical properties is called a functional group. It is the most reactive site of a carbon compound.

Homologous series The family of organic compounds having same functional group, similar chemical properties and the successive members of which differ by CH₂ group is called a homologous series.

Characteristics of a homologous series 

1.     All the members can be represented by same general formula.

2.     The molecular formulae of two successive members differ by CH₂ group or by 14u.

3.     All the members have same functional group.

4.     All the members show similar chemical properties.

• The melting and boiling points of the members of homologous series increase gradually because their molecular masses increase.

Allotropy The phenomenon in which one element exists in two or more forms having same chemical properties but different physical properties is called allotropy. The substances that show allotropy are carbon, sulphur, etc.

Allotropes The different forms of an element having same chemical properties but different physical properties are called allotropes.

Isomerism The phenomenon in which a compound can be represented by different structures having different properties is called isomerism.

Isomers The compounds which can be represented by different structures having different properties are called isomers.
IUPAC – International Union of Pure and Applied Chemistry.

Combustion The process of heating a substance strongly in the presence of excess of oxygen or air is called combustion.

• Carbon and carbon compounds release carbon dioxide, water and a large amount of heat and light on burning. 

C + O₂  CO₂ + Heat and Light 
CH₄ + O2  CO₂ + H₂O + Heat and Light
C₂H₅OH + O₂  CO₂ + H₂O + Heat and Light

• Saturated hydrocarbons generally give a clean blue flame because complete combustion of these substances takes place.
• Saturated hydrocarbons burn with a yellow flame with lots of black smoke due to the incomplete combustion of carbon contents.
• Condition in which saturated carbon compounds burn with sooty flame – If a saturated carbon compound is burnt in limited (insufficient) supply of air, it burns with sooty flame due to incomplete combustion.
• The gas/kerosene stoves used at homes have inlets for air so that a sufficient oxygen rich mixture is burnt to give a clean blue flame with a lot of heat.
• Sometimes bottoms of cooking vessels get blackened due to incomplete combustion of gas/kerosene. It means the holes are blocked. This problem can be removed by cleaning the burner by opening holes.
• The pollutants released in the environment by burning coal and petroleum are oxides of sulphur and nitrogen e.g. SO₂ , NO, NO₂ , etc.
• Combustion of hydrocarbons is regarded as oxidation reaction because during combustion, carbon is oxidised to CO₂ and hydrogen is oxidised to water by addition of oxygen.
• Only the gaseous substances produce flame on burning.
• Wood and charcoal are solid but they produce flame when ignited because when they are ignited the volatile substances present vaporize and burn with a flame in the beginning only.
• Fossil fuels The fuels formed by the dead animals and plants buried under the earth millions of years ago due to intense heat and pressure are called fossil fuels. E.g. coal and petroleum.
• When an alcohol is heated in the presence of alkaline KMnO₄ (or acidified K₂ Cr₂ O₇ ) then corresponding carboxylic acid is formed.

• Addition reaction The reaction which involves addition of two reactants to form a single product is called an addition reaction. Only unsaturated hydrocarbons perform addition reactions.

CH₂ = CH₂ + Cl₂  CH₂Cl – CH₂Cl

• Industrial application of addition reaction Addition reaction is commonly used in the hydrogenation of vegetable oils using a nickel catalyst to form vegetable ghee.

Vegetable oil (liquid) + H₂ Ni (473K) Vegetable ghee (solid)

Saturated fatty acids are harmful for health so oils containing unsaturated fatty acids should be used for cooking because Saturated fats increase the level of bad cholesterol (low density lipoprotein LDL) in blood which sticks to the walls of arteries and causes heart diseases.

Substitution reaction The reaction which involves direct replacement of an atom or group of atoms in an original molecule is called substitution reaction. Only saturated hydrocarbons perform substitution reactions.

CH₄      +        Cl₂   CH₃Cl      +        HCl

Functional group	Symbol/formula	Prefix/suffix	Compound name
Halo	-Cl,  -Br,  - I	Halo (prefix)	Haloalkane
Alcohol	-OH	-ol	Alkanol
Aldehyde	-CHO	-al	alkanal
Ketone	- CO -	-one	Alkanone
Carboxylic	-COOH	-oic acid	Alkanoic acid

Simplest compound Common name IUPAC name Formula Alcohol Methyl alcohol Methanol CH3OH Aldehyde Formaldehyde Methanal HCHO Ketone Acetone Propanone CH3COCH3 Carboxylic acid Formic acid Methanoic acid HCOOH alkane Methane Methane CH4 Alkene Ethylene Ethene C2H4 alkyne Acetylene Ethyne C2H2

ETHANOL (CH₃CH₂OH or C₂H₅OH)

Physical properties 

1.     It is liquid at room temperature.

2.     It is colourless and has distinct smell and burning taste.

3.     It is soluble in water in all proportions.

Chemical properties

1.     It reacts with sodium to form sodium ethoxide and hydrogen gas.

2CH₃CH₂OH + 2Na  2CH₃CH₂ONa + H₂

2.     It reacts with hot concentrated H2SO4 to give ethene.

CH₃CH₂OH  CH₂=CH₂ + H₂O

USES

1.     It is used in all alcoholic drinks like wine, beer, etc.

2.     In the form of rectified spirit (95% alcohol + 5% water), it is used as an antiseptic for wounds.

3.     It is used in medicines like tincture iodine, cough syrups, tonics etc because it is a good solvent.

4.     In cold countries it is used as antifreeze in automobiles.

Harmful effects of ethanol

1.     Consumption of its small quantity causes drunkenness. 

2.     It depresses the central nervous system which results in mental confusion and drowsiness.

3.     It damages liver and kidney.

4.     It decreases the sense of judgment and sense of timing.

5.     It increases crime in the society.

Denatured alcohol To prevent the misuse of ethanol produced for industrial use, it is made unfit for drinking by adding poisonous substances like methanol, copper sulphate, etc. it is called denatured alcohol.

ETHANOIC ACID (acetic acid or vinegar, CH₃COOH)

Physical properties. 

1.     It is a colourless and pungent smelling liquid.

2.     Its melting point is 290K so it often freezes during winter and looks like glacier. Therefore, it is also known as glacial acetic acid.

3.     It is soluble in water in all proportions.
5% to 8% solution of Ethanoic acid in water is called vinegar.

Chemical properties 

1.     Reaction with alcohol. Ethanoic acid reacts with ethanol in the presence of an acid to give ester.

CH₂COOH + C₂H₅OH Acid CH₃COOC₂H₅ + H₂O

2.     Reaction with base. Ethanoic acid reacts with sodium hydroxide to give sodium ethanoate (sodium acetate) and water.

CH₃COOH + NaOH CH₃OONa + H₂O

3.     Reaction with carbonates and bicarbonates. Ethanoic acid reacts with carbonates and bicarbonates to salt carbon dioxide and water.

2CH3COOH + Na2CO3 2CH3COONa + CO2 + H2O
CH3COOH + NaHCO3 CH3COONa + CO2 + H2O

Esterification The reaction between a carboxylic acid and an alcohol to form an ester is called Esterification reaction.

CH₂COOH + C₂H₅OH Acid CH₃COOC₂H₅ + H₂O

• The reaction between the ester and hot base to give original alcohol and carboxylic acid back is called saponification reaction because this reaction is used in preparing soaps.

CH₃COOC₂H₅ NaOH CH₂COOH + C₂H₅OH 

The product formed when a carboxylic acid reacts with an alcohol having the formula R-COO-R’ is called an ester. Esters are sweet smelling substances. They are widely spread in nature. The smell of fruits and flowers is due to the presence of esters. Esters are used as flavorings agents and in making perfumes.

Cleansing action of soap The molecules of soap are sodium or potassium salts of long chain of carboxylic acids. The hydrocarbon tail being hydrophobic reacts with oil or grease while the ionic end being hydrophilic reacts with water. As a result micelles are formed. They form an emulsion in water.
When the surface of clothes is beaten or agitated, micelles are thrown away and the cloth is cleaned.

Micelle The cluster of about 100 – 200 molecules with hydrophilic ends on the surface of cluster and hydrophobic ends towards the centre, is called a micelle. 

Soaps	Detergents
Soaps are sodium salts of long chain carboxylic acids.	Detergents are sodium salts of long chain sulphonic acids.
Soaps do not form leather with hard water.	Detergents form leather with hard water.
Soaps are biodegradable.	They are non biodegradable.
Soaps do not have strong cleansing action.	They have strong cleansing action.
These are prepared from animal fats.	They are prepared from hydrocarbons of petroleum.

Advantage of soaps over detergents Soaps are biodegradable so they do not produce pollution. While detergents being non biodegradable produce pollution.

Advantage of detergents over soaps Detergents can be used in hard water. Also, they have strong cleansing action. While soaps have weak cleansing action and they cannot be used in hard water.

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