CHEMISTRY FOR AIEEE

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Chemistry for AIEEE

Wednesday, April 23, 2008

Cracking AIEEE Tips from Orkut AIEEE community

http://www.orkut.com/CommMsgs.aspx?cmm=10597861&tid=2593734643528395271

ABHI: Feel the

How can u crack AIEEE

Hi everyone. I am abhishek. I cracked AIEEE last year. Now I would like to tell you all how an average student can crack AIEEE if he plans in a proper way.

Some rules to crack any comp exam..

You must have a deep knowledge of the syllabus.

You must have done deep analysis of the exam

You must have seen the changing pattern of the exam in last few years

You must have a right strategy for the exam

You must be confident to crack it

Most importantly dont panic, No one is perfect. Stay calm on the exam day....

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Now talking about AIEEE exam. Cracking AIEEE or not totally depends on time management while giving exam. For it right choice of the questions must be done so that you dont waste time on difficult question and leaving them without getting the answer and wasting 1 to 2 minutes. Remember most of the student dont clear AIEEE b'coz they make this mistake....

If you see the AIEEE 2007 paper you will find that there were 120 questions each carrying 3 marks. The total marks were 360 out of which if you had scored 200+ marks you were always safe to get a good college,. After doing a deep analysis of the last year paper I have found that in physics most of the questions were from electricity, magnetism, modern physics and mechanics.

About 75 to 80% paper was covered from these topics. 35% questions were easy and 60% were medium. So if you attempt 65% questions ie 26 questions with 4 wrong out of 40. This means your score is 76-4=72 marks. Now these 26 questions you had to do in 50 minutes. means 2 minutes for each question which is quite a fair time to solve the questions as some of the questions are conceptual. So if you can attempt your mocks by following this strategy for physics it will help you and try to implement it in your AIEEE exam...

Talking about chemistry, This is the most broad branch but scoring one,

Doing analysis of last year. Physical chemistry had 21 questions, organic 12 and inorganic 7. What this shows that physical chemistry is the most important part to crack AIEEE as the examiners love it to put it in Question paper. student also try to put too much time in doing organic and leaving Physical..

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Important topics for Physical chemistry

Atomic structure and chemical bonding 4 questions

Thermodynamics 4 questions

Equilibrium 3 questions

Nuclear chemistry and electro chemistry 2 questions each.

They consist 15 questions out of which if you are doing 12 questions out of which 10 are right.
your score for physical is 28.

Talking about Organic chemistry

Organic chemistry- basic principles 2 questions

Stereochemistry 2 questions

Hydrocarbons 2 questions

If you are attempting 10 questions in this section having 8 right. your score for this section is 22.

Talking about inorganic part. p , d and f block are most important. Still if your are sticking with these three topics, you are able to do 8 questions. Assuming your score for this section is 22.

Lets doing the total of your score for Chemistry 28+22+22=72
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Now comes the most difficult part. MATHS

Doing the analysis. I have found that calculus and algebra are the most coming topics in the previous year papers of AIEEE. Last year 20 questions were there from these two topics. If you had attempted 14 questions with 11 right and 3 wrong from these two topics. Your score was 30 in this part.And if you had spent 30 minutes for these 14 questions. you were still left with 20-25 minutes. You should had gone for 3D, vectors and cordinate geometry. These three topics had 12 questions and if you had done 8 questions in remaining 20 minutes qith 6 right. Your score for these topics was 14 making your total score for Maths 44. This is a rough calculation. Score of 50 can be easily obtained.

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So your total score in AIEEE is 72+72+50= 194 which could had easily fetched a seat in a very nice institute.

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One more important thing for you all.......

Never attempt maths first. It will surely ruin your performance in the exam.....

Try to attempt chemistry in the first hour as it has some easy questions and if you can solve these question in the first hour, you will feel confident with more accuracy,. this has been proved that if you are confident then your efficiency increases,,,,,,,,,

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inorganic and organic also cover huge part in AIEEE exam. What I think is that most important thing is how can u get through cut off. This can be done alone with organic and inorganic. As you also know that chemistry is the most scoring of all.. Do one thing just read the concepts of thermodynamics and chemical equilibrium. You can see that some questions from these parts are just conceptual type. So just clear your concepts and you can do 40% questions from these two topics.

Believe me those who crack AIEEE are those who does well in chemistry. In these coming days concentrate more on chemistry. If you are studying 10 hours a day. Study atleast 4 hours for chemistry. With in these 4 hours brush up your concepts of organic and inorganic for 3 hours and give 1 hour for physical. If after this you can do 8 questions from physical and as you said you are good in organic and inorganic then you can do better in these sections. Then surely you are clearing your Cut off for Chemistry.

Always do theoretical questions firstly and after this question which require calculation. its a nature of human that if you do few questions in the beginning then positive energy will come inside you and your efficiency will increase.....

Never attempt numerical questions in the first 10 or 15 minutes of your exam.......

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Talking about mocks. Do 5 mocks before exam. It will help you to know where are you wasting your time in doing the exam. Dude do mocks. They are most important to crack AIEEE

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Tomorrow is 18th, leaving day before AIEEE you are left with 8 days. Do one thing revise all the formulas and the important points which you have marked within these 8 days. Remember that study all three subjects everyday. I hope that you have marked important points. Make a time table for the coming six days to revise your syllabus. Time table must be like that you are giving max time to your strengths. Like if your strength in Physics is Electrostatics then revise electro giving enough time to it so that you are sure about every concept about it. If you are not sure about modern physics then whatever you have studied about it, study it. Dont study anything new about anything.

Try to cover your syllabus within next 6 days. Now you have revise your syllabus once.
On seventh day, do two mocks before night. Try to analyze where are you making mistakes, I mean where are you wasting your time. Which section you are doing best. Whatever mistakes you make in first paper try to remove in second. In this you will be better prepared for the main exam. What most students do is that they revise whole of the syllabus but never attempt a mock and thus they always make mistake in main exam and thus they loose the track..

After this at night and on 8th day again revise some important points or you can mark some important points on these six days to revise on the 8th day.

After this, on day before AIEEE dont study anything. Calm yourself, Say to yourself I am excited about AIEEE and I can crack it easily. Go to temple and play with your friends. Dont talk anything about AIEEE with others. Dont ask your friend how much they have studied. It will cause much pressure. You can even watch a film on 26th.

Then sleep for atleast 8 hours and go to your center with full confidence.

Cracking any exam depends on two things

How you study

Your attitude....

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For maths, I would recommend you R.D sharma objective. This is a very good book. Every type of questions are covered in this book.

For Physics H.C verma is best book to clear your concepts. After attempting questions from it you can take any objective book or AIEEE explorer and search for the questions in the net. There are some magzines like Physics Today which will help you in doing mocks and new questions. This is a monthly magzine which must be done. It is a very nice one.

For chemistry study NCERT book. Well I believe that chemistry portion in AIEEE is more conceptual paper than numerical, so I believe that P. Bahadur will not help you upto huge level . But still do short questions from it rather than trying big numerical from it.
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AIEEE Model paper published in eenadu 19 April 2009

Wednesday, February 13, 2008

AIEEE Chemistry Unit 13 Hydrogen

UNIT 13 HYDROGEN
Position of hydrogen in periodic table, isotopes, preparation, properties and uses of hydrogen;
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Period 1 Group 1
Atomic Number 1
Symbol H
Atomic Weight 1.0079
Discovery Cavendish, 1766
Hydrogen was prepared for many years before it was recognized as a distinct element.
Electron Configuration 1s¹
Word Origin Greek: hydro, water; genes, forming
Named by Lavoisier.

Isotopes

Protium (0 neutrons), Deuterium (1 neutron), and Tritium (2 neutrons).
Properties

Hydrogen is the most abundant element in the universe.

Hydrogen is a colorless, odorless, combustible gas.

Hydrogen gas is so light and diffusive that uncombined hydrogen can escape from the atmosphere.

Hydrogen gas ordinarily is a mixture of two molecular forms, ortho- and para-hydrogen, which differ by the spins of their electrons and nuclei.
Normal hydrogen at room temperature consists of 25% of the para form and 75% of the ortho form. The ortho form cannot be prepared in the pure state. Since the two forms of hydrogen differ in energy, their physical properties also differ.

Uses

Hydrogen is important in the proton-proton reaction and carbon-nitrogen cycle. Liquid hydrogen is used in cryogenics and in the study of superconductivity.
Great quantities are used for the fixation of nitrogen from the air in the Haber ammonia process.
Hydrogen is use in welding, for the hydrogenation of fats and oils, in methanol production, in hydrodealkylation, hydrocracking, and hydrodesulfurization.
Other applications include producing rocket fuel, filling balloons, making fuel cells, producing hydrochloric acid, and reducing metallic ores.
Deuterium is used as a moderator to slow down neutrons and as a tracer.
Tritium is used in the production of the hydrogen (fusion) bomb.
Tritium is also used in making luminous paints and as a tracer.

Sources

Hydrogen occurs in the free state in volcanic gases and some natural gases. Hydrogen is prepared by steam on heated carbon, decomposition of certain hydrocarbons with heat, action of sodium or potassium hydroxide on aluminum electrolysis of water, or displacement from acids by certain metals.

AIEEE Chemistry Unit 13B Water and Heavy Water

Physical and chemical properties of water and heavy water;

Heavy water is water that contains the heavy isotope of hydrogen called deuterium (chemical symbol D). The deuterium atom weighs about twice as much as ordinary hydrogen atom. Heavy water, also called deuterium oxide, makes up about 1 part in 5000 of ordinary water.

It was first separated from ordinary water in 1932 by G N Lewis, a chemist at the University of California.

Because of the difference between the weights of the two kinds of hydrogen atoms, the physical properties of heavy water differ from those of ordinary water. Heavy water freezes at 3.82oC and boils at 101.42oC.

Ice made from heavy water sinks in normal water.

Heavy water is useful in some kinds of nuclear reactors. It acts as a moderator to control the energy of the neutrons in a chain reaction. Seeds will not germinate in heavy water, and some animals, including tadpoles, cannot live in it.

Unit 13C Hydrogen Peroxide

Structure, preparation, reactions and uses of hydrogen peroxide;

Hydrogen peroxide, H2O2, was first discovered by Thenard among others in 1818 by reacting acids with barium peroxide, BaO2.

It resembles water in appearance being colourless in small quantities but blue when observed in thick layers.

It decomposes to oxygen and water and this decomposition is promoted by heat and alkalis.

Commercial grade H2O2 usually contains small amounts of stabilizers.

Hydrogen peroxide is a strong oxidising agent and is widely used as a bleaching agent. In dilute solutions it is an efficient antiseptic. The uses of hydrogen peroxide have been changing in recent years.

Uses

Textile bleaching
Chemical production
Wood pulp bleaching - Major user
Environmental uses
Miscellaneous uses

Production process

Hydrogen peroxide is produced by reducing alkylanthraquinone with hydrogen in the presence of a catalyst to the hydroquinone. After the catalyst has been removed to prevent decomposition of the hydrogen peroxide, the hydroquinone is oxidised, usually with air, back to quinone with a resultant co-production of hydrogen peroxide.

The hydrogen peroxide is removed and purified and the quinone is regenerated and returned to the reaction.

The anthraquinone must be dissolved in a suitable solvent for the hydrogenation, oxidation and extraction steps - this is usually referred to as the working solution. The solvent is usually a mixture because quinones dissolve readily in non-polar aromatic solvents, such as alkylbenzene, whereas hydroquinones dissolve well in polar solvents, such as alcohols and esters. A variety of different mixtures are in use but the aim is to satisfy a number of criteria, namely good solubility of both quinone and hydroquinone, good stability in both hydrogenator and oxidiser, low solubility in water and aqueous hydrogen peroxide solutions, sufficiently higher or lower density than water to ensure separation of the two phases during extraction, low volatility, high distribution coefficient for hydrogen peroxide in the solvent-water system and low toxicity. 1

In the hydrogenator, the working solution is reacted with hydrogen in the presence of a catalyst. The process is exothermic and the heat of reaction is removed by cooling the working solution before it enters the hydrogenator, by cooling the reactor during hydrogenation and/or by cooling the hydrogenated working solution.

After the hydrogenation reaction, the working solution must pass through a filtration stage to remove all traces of catalyst. Even small traces of catalyst in the oxidation and extraction stages lead to significant losses of hydrogen peroxide and could present safety problems. During the oxidation stage, air is passed through the hydrogenated working solution to convert the dissolved hydroquinones to quinones and form the hydrogen peroxide. The air outlet is passed over activated carbon adsorbers to recover solvent.

Crude hydrogen peroxide is extracted from the oxidised working solution by treating with water. The working solution is then regenerated and fed back to the front of the process and the crude hydrogen peroxide (15-35 wt%) is fed to a treatment unit where the concentration is increased to 50-70 wt%.

Friday, February 1, 2008

Link for AIEEE online sample test/question papers

http://easportsfifa08.blogspot.com/2008/01/free-eamcetaieee-online-test-papers.html

I downloaded a paper.

Thursday, January 31, 2008

AIEEE Chemistry Unit 14A S-Block Elements

ALKALI AND ALKALINE EARTH METALS
Group - 1 and 2 Elements:
General introduction, electronic configuration and general trends in physical and chemical properties of elements,

The alkali metals are the elements located in Group IA of the periodic table.

The alkali metals have many physical properties common to metals, but their densities are lower than those of other metals.

Alkali metals have one electron in their outer shell.

This gives them the largest atomic radii of the elements in their respective periods.

Their low ionization energies result in their metallic properties and high reactivities.

An alkali metal can easily lose its valence electron to form the univalent cation.

Alkali metals have low electronegativities.

They react readily with nonmetals, particularly halogens.

ALKALINE EARTH METALS

The six alkaline earth metals—beryllium, magnesium, calcium, strontium, barium, and radium—comprise Group 2 on the periodic table of elements.

They are in Group 2 beside the alkali metals in Group 1, and as their names suggest, the two families share a number of characteristics, most notably their high reactivity.

Magnesium and calcium have a number of uses, ranging from building and other structural applications to dietary supplements.

In fact, both are significant components in the metabolism of living things—including the human body.

Barium and beryllium have numerous specialized applications in areas from jewelry to medicine, while strontium is primarily used in fireworks.

Radium, has radioactive qualities.

AIEEE Chemistry Unit 14C Compounds of Sodium

Preparation and properties of some important compounds - sodium carbonate, sodium chloride, sodium hydroxide and sodium hydrogen carbonate;

Sodium carbonate (Na2CO3)

Sodium carbonate exists as anhydrous (Na2CO3) and also as hydrated salt. The decahydrated salt (Na2CO3.10H2O) is known as washing soda while the anhydrous salt is called soda ash.

Occurrence

Large deposits of this salt occur in Owens lake in California and Lake Magadi in British East Africa. It occurs native as Na2CO3.NaHCO3.H2O in Egypt.

During hot weather, soda is also collected from a large number of alkaline lakes.

Manufacture of Sodium Carbonate

Ammonia-soda process (or Solvay process)

This process is the most popularly used method. As Ernest Solvay, the Belgian chemical engineer, devised it in 1864 it is known as Solvay process.

Raw materials

The raw materials for this process are common salt, ammonia and limestone (for supplying CO2 and quicklime).

Principle

When carbon dioxide is passed into a concentrated solution of brine saturated with ammonia, ammonium bicarbonate is produced,

The ammonium bicarbonate then reacts with common salt forming sodium bicarbonate,

Sodium bicarbonate being slightly soluble (in presence of sodium ions) gets precipitated. The precipitated sodium bicarbonate is removed by filtration and changed into sodium carbonate by heating.

The mother liquor remaining after the precipitation of sodium bicarbonate contains ammonium chloride. This is used to regenerate ammonia (one of the raw materials) by steam heating with milk of lime.

Lime is obtained by heating limestone.

Ammonia and carbon dioxide liberated are utilized in making the whole process cyclic and continuous. The only by-product in the process is calcium chloride.

Sodium chloride (NaCl)

Sodium chloride (NaCl) or common salt is an ionic crystal consisting of equal numbers of sodium and chlorine atoms and is an essential component in the human diet, being found in blood sweat and tears.
Occurrence
Sodium chloride is abundant and can be found naturally occurring. It can be found in the mineral halite (pure rock salt) as well as in mixed evaporates in salt lakes.
Sea water also contains 2.7% by weight salt and constitutes 80% of the dissolved minerals in sea water.
Production
Sodium chloride is mined or obtained from brine, when water is added to salt deposits.
Alternatively, it is obtained from sea water. This is commonly known as sea salt and constitutes most table salt. It also contains some impurities.

Sodium chloride:
• Has a cubic crystalline structure
• Is clear when pure, although may also appear white, grey or brownish, depending upon purity
• Is soluble in water
• Is slightly soluble in other liquids
• Is odourless
• Has a characteristic taste
• Molten sodium chloride is an electrical conductor

Symbol NaCl

Atomic Weight 58.44
Eutectic Composition 23.31% NaCl
Melting Point 801°C
Boiling Point 1465°C
Density 2.17g/cm3
Refractive Index 1.5442
Mohs Hardness 2.5
Co-Efficient of Thermal Expansion @ 0°C 40x10-6
Solubility g/100g H2O at 0°C 35.7

Sodium chloride is used for:
• Windows for analytical instruments
• De-icing
• Food and cooking
• High power lasers
• To produce chlorine and sodium
• Historically it has been used as a form of currency

Sodium hydroxide

sodium hydroxide chemical compound, NaOH, is a white crystalline substance that readily absorbs carbon dioxide and moisture from the air.
It is very soluble in water, alcohol, and glycerin.

It is a caustic and a strong base
It is commonly known as caustic soda, lye, or sodium hydrate.
The principal method for its manufacture is electrolytic dissociation of sodium chloride; chlorine gas is a coproduct.
Small amounts of sodium hydroxide are produced by the soda-lime process in which a concentrated solution of sodium carbonate (soda) is reacted with calcium hydroxide (slaked lime); calcium carbonate precipitates, leaving a sodium hydroxide solution.
The major use of sodium hydroxide is as a chemical and in the manufacture of other chemicals; because it is inexpensive, it is widely used wherever a strong base is needed.
It is also used in producing rayon and other textiles, in making paper, in etching aluminum, in making soaps and detergents, and in a wide variety of other uses.

Sodium Bicarbonate NaHCO-3

Sodium Bicarbonate, commonly called baking soda, is a white odourless, crystalline solid, completely soluble in water but slightly soluble in ethanol. It is the mildest of all sodium alkalis.

It is prepared from purified sodium carbonate or sodium hydroxide solution with passing carbon dioxide which is bubbled into the solution of pure carbonate, and the bicarbonate precipitates out to be dried as the bicarbonate is less soluble than the carbonate.

Sodium bicarbonate is also made as an intermediate product in the Solvay process (described above)which is to make sodium carbonate from calcium carbonate by treating sodium chloride with ammonia and carbon dioxide.

The major use of sodium bicarbonate is in baking powders.
Sodium Bicarbonate plays an important role in the products of many diverse industries with functions of releasing CO2 when heated above about 50 C or when reacted with a weak acid makes sodium bicarbonate a key ingredient in food leavening as well as in the manufacture of effervescent salts and beverages.
It can react as an acid or a base in water treatment.
In health and beauty applications, mild abrasivity and ability to reduce odors chemically by neutralizing the acid by-products of bacteria are utilized.
It is also used in treating wool and silk, fire extinguishers, pharmacy, leather, oredressing, metallurgy, in cleaning preparations and industrial & chemical processe.

Uses

food & food processing, beverages , pharmaceuticals , animal foodstuffs , household cleaning products , rubber & plastics foam blowing , fire extinguishers & explosion suppression , effluent & water treatment, flue gas treatment , oil drilling , industrial & chemical processes

Thursday, January 24, 2008

AIEEE Chemistry Unit 15A P Block Elements

Group - 13 to Group 18 Elements

General Introduction: Electronic configuration and general trends in physical and chemical properties of elements across the periods and down the groups; unique behaviour of the first element in each group.

AIEEE Chemistry Unit 15B Group 13 Elements

Groupwise study of the p–block elements Group-13:
Preparation, properties and uses of boron and aluminium;
Structure, properties and uses of borax, boric acid, diborane, boron trifluoride, aluminium chloride and alums.
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AIEEE Chemistry Unit 15C Group 14 Elements

Group - 14:
Tendency for catenation; Structure, properties and uses of allotropes and oxides of carbon, silicon tetrachloride, silicates, zeolites and silicones.

AIEEE Chemistry Unit 15D Group 15 Elements

Properties and uses of nitrogen a
nd phosphorus;
Allotrophic forms of phosphorus; Preparation, properties, structure and uses of ammonia, nitric acid, phosphine and phosphorus halides, (PCl3, PCl5);
Structures of oxides and oxoacids of nitrogen and phosphorus.
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AIEEE Chemistry Unit 15E Group 16 Elements

Group - 16:
Preparation, properties, structures and uses of dioxygen and ozone; Allotropic forms of sulphur; Preparation, properties, structures and uses of sulphur dioxide, sulphuric acid (including its industrial preparation); Structures of oxoacids of sulphur.

AIEEE Chemistry Unit 15F Group 17 Elements

Group - 17:
Preparation, properties and uses of chlorine and hydrochloric acid; Trends in the acidic nature of hydrogen halides; Structures of Interhalogen compounds and oxides and oxoacids of halogens.

AIEEE Chemistry Unit 15G Group 18 Elements

Occurrence and uses of noble gases; Structures of fluorides and oxides of xenon.

Helium
Neon
Argon

AIEEE Chemistry UNIT 16 d – and f – BLOCK ELEMENTS

Transition Elements :
General introduction, electronic configuration, occurrence and characteristics,

A transition element may be defined as an element which in its elementary form or in at least one of its oxidation states, possesses partially filled d orbitals in its penultimate shell.

The definition excludes zinc, cadmium, and mercury from the transition elements, however their properties are an extension of the properties of transition elements, they are generally considered along with transition elements.

Three series of elements are formed by filling the 3d, 4d, and 5d shells by electrons.

First series or 3d series: Scandium to Zinc
Second series or 4d series: Yitrium to cadmium
Third series or 5d series: Lanthanum to hafnium to mercury

Transition Metals
The ten elements from Scandium to Zinc form the first transition metal series. They closely resemble each other and are hard, dense, shiny metals with high melting and boiling points. They readily form alloys and have other properties in common. Crossing the period from Sc to Zn there is a small decrease in atomic radius and increase in electronegativity and ionisation energy. Most of the properties of transition metals are related to their electronic structures.

Electronic Structure
Transition elements are characterised by having a partially filled d sub-shell

Sc [Ar] 3d1 4s2

Ti [Ar] 3d2 4s2

V [Ar] 3d3 4s2

*Cr [Ar] 3d5 4s1

Mn [Ar] 3d5 4s2

Fe [Ar] 3d6 4s2

Co [Ar] 3d7 4s2

Ni [Ar] 3d8 4s2

*Cu [Ar] 3d10 4s1

Zn [Ar] 3d10 4s2

*Note that in Cr the arrangement [Ar] 3d5 4s1 with half-filled 3d and 4s sub-shells is more stable than [Ar] 3d4 4s2.

In Cu [Ar] 3d10 4s1 with a completely filled 3d sub-shell and a half-filled 4s sub-shell is more stable than [Ar] 3d9 4s2.

General characteristics

1. They are hard and brittle metals.
2. They have a high melting and boiling points and have higher heats of vaporization than non transition elements.
3. The transition elements have very high densities as compared to the metals of groups I and II (s-block).
4. The first ionization energies of d-block elements are higher than those of s-block elements but are less than those of p-block elements.
5. They are electropositive in nature.
6. Most of them form coloured compounds.
7. The have good tendency to form complexes.
8. They exhibit several oxidation states.
9. Their compounds are generally paramagnetic n nature.
10. They form alloys with other metals.
11. They form interstitial compound with elements such as hydrogen, boron, carbon, nitrogen etc.
12. Most of the transition metals such Mn, Ni, Co, Cr, V, Pt etc. and their compounds have been used as good catalysts.

Oxidation States
Transition metals form ions which are characterised by having a partially filled d sub-shell. In case of 3d series electrons in 4s as well as electrons in 3d participte in reactions. Lower oxidation states represent the participation of electrons in 4s only. Higher oxidation states result when electrons in 3d also participate.

The common oxidation states of various elements are:

Sc 3
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Ti 2 3
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V 2 3 4 5
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Cr (1) 2 3 (5) 6
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Mn 2 3 4 (5) 6 7
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Fe 2 3 (4) (5) (6)
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Co 2 3 (4)
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Ni 2 3
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Cu 1 2
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Zn 2
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Oxidation states in brackets are unstable

Sc and Zn are not typical transition metals as they only have one oxidation state which does not have a partially filled d sub-shell. (Sc3+ [Ar], Zn2+ [Ar] 3d10).

Common oxidation states are +2 and +3, with the +2 state more common towards the end. The higher oxidation states are shown in compounds with electronegative elements like O, Cl or F (e.g. Cr2O7^2- [+6], MnO4^- [+7]).

Variable oxidation state is found because of the small difference in energy between the 3d and 4s sub-shells. This allows varying numbers of electrons to be used in bonding. When forming ions transition metals lose electrons from the 4s sub-shell before the 3d.

AIEEE Chemistry Unit 16B First Row Transition Elements

Syllabus

general trends in properties of the first row transition elements - physical properties, ionization enthalpy, oxidation states, atomic radii, colour, catalytic behaviour, magnetic properties, complex formation, interstitial compounds, alloy formation;

AIEEE Chemistry Unit 16C K2Cr2O7 and KMnO4

Potassium Dichromate and Potassium Permanganate

Syllabus

Preparation, properties and uses of K2Cr2O7 and KMnO4.

Potassium dichromate

K2Cr2O7.

It's molecular weight is 294.19 g/mol.
Melting point: 3980C.
Boiling point: 5000C

Potassium dichromate's state at room temperature is solid.
Potassium dichromate is ionic.
It's molecular geometry is tetrahedral.
Potassium dichromate is crystalline ionic solid with a red-orange color.

It's uses include dyeing, staining, tanning leather, as bleach, oxidiser, depolariser for dry cells, etc.

Medically it has been used externally as an astringent, antiseptic, and caustic.

It has also been used in photographic screening.
It is used as an anti-pain remedy in homeopathy.
It is used ini ethonal determination.

When taken internally, it is a corrosive poison. Hence it is poisonous and hazardous to health.

Potassium Permanganate
KMnO4

Molecular Weight- 158.03 g

Melting Point- 270°C

Boiling Point- Doesn't boil

State - at room temperature solid - Purple, sweet flavor, and crystals.

Ionic

Uses- disinfectant, propellant in rockets, and is used in torpedos.

AIEEE Chemistry Unit 16D - Inner Transition Elements

Syllabus

Inner Transition Elements :
Lanthanoids :
Electronic configuration, oxidation states, chemical reactivity and lanthanoid contraction.

Actinoids :
Electronic configuration and oxidation states.