* HUGE ESSAY COMING UP LOL*
* IF SOMEONE HAS A DOUBT IN STOICHOMETRY OR ANYTHING ELSE, FEEL FREE TO MSG ME*
*Tips continued :*
*CHEMISTRY* Chapter 1 :
Do all the definitons, on a paper make a chart and with arrows mark trends. Make a table which tells the factors, Highest , lowest. Write keypoints of give reason answers eg : Chlorine has more EA than Fluorine : F - small size - electro repulsion
Chapter 2 :
Do the definitons. Structure of all electrovalent and Covalent are similar, go through them once if you are confused, DON'T forget to write the electrovalency, do the lone pair effect and NH4+ and H3O+ coordinate bonds. Make a two column table and write the difference in properties of electrovalent and covalent compounds in KEYWORDS ( I am emphasising because long answers are boring to read , takes time but keywords can instantly make you remember the crux of the matter).
Chapter 3 :
Do all definitions . Make a table and write the general formulae of preparation of acids and base : such as H2 + halogen = acid; Metal + O2 = Base ;(there are more)
Go through the uses and the pH paper page. Learn the change in colours of indicators and the difference between them. Learn the SI Unit of pH and pH = -log H+
For salts learn solublity , just the general formula of all salt preparation ( w/ insoluble and soluble / dilute and conc and temp written) . With this you can make your own equations. Go through the examples once. Go through the preparation of specific salts with emphasis on FeCl3. Learn the properties, WOC , deliquiscence, efflorescence , Hygroscopy and Hydrolysis - learn the pH of solutions.
For Stoichometry - Learn the 2 laws , go through examples and understand what it means : Gay Lussac's is only for volume , Avogadro's can be of moles / mass / volume
Then solve last 10 years and behind book questions.
For Electrolysis : Learn all definitions and differences, see the examples : mainly electrovalent / polar covalent compounds are strong electrolytes other's are not. LEARN the names of NON electrolytes and WEAK. Don't get confused here. Understand that covalent compounds are molecules so they don't conduct electricity but in aq. state, they form ions by ionisation and conduct ; Learn that ionic compounds in solid state don't conduct and in molten/aq state - they form ions (So you can use this for any compound example they give). By heart the electrochemical series for both - cations and anions. Learn it like this : ( Note : 1st letter stand for element names)
Kings (K)
Cannot ( Ca)
Make (Mg)
A (Al)
Zebra (Zn)
I (Iron - Fe)
Like (Lead - Pb)
His ( H)
Car (Cu)
Horns (Hg)
So ( Silver - Ag)
Good ( Gold - Au)
Just learn the Selective discharge page.
Make a table with columns named : Cathode , Anode , Electrolyte , Anode Reaction and Product, Cathode reaction and Product , Give reasons , observations . Write for all 4 - Molten PbBr2 , CuSO4 ( inert and active electrode) and acidified water.
The electroplating and refining is pretty much logical if you understood electrolysis. Read through it once and you will surely get it.
For Metallurgy :
Read through the properties part. Write down the ores on a paper with chemical formulae. Write down the methods of concentration, their principle and ores used for them. Roasting and Calcination is pretty easy. Do reduction and learns reason why electrolysis / agent / heat is used.
For refining, learn the method names and read the explanation. Learn the metals and the places :
Distillation - Iron retort
Liquation - Hearth
Oxidation - Bessemer converter
Electrolytic - Voltameter
Just read the metallurgy of Zn and Fe. Baeyer's process is pretty important. On a page write down the equations, reasons, electrolyte, cathode , anode , products and reasons - write keywords only to save time.
Just read through the properties and for uses - write them down with reasons for use. Make a table for Al, Zn and Fe and do this. Go through hardening, annealing and rusting. Make a table and write down the constituents of alloys ( don't do %) , properties and uses. Solve last 10 years definitely for this chap.
For analytical : Learn the colours of ions - these help a lot as sulphates / chlorides / nitrates are based on these colours. Each ppt (Hydroxide) has its own adjective.
Fe(OH)2 is dirty green
Fe(OH)3 is reddish - brown
Cu(OH)2 is pale blue
Zn(OH)2 is gelatinous white
Mg(OH)2 is dull white ( NOT IN SYLLABUS)
Pb(OH)2 is chalky white.
Learn the excess equations and colours of excess solution.
Remember - Pb / Zn react with excess NaOH
Zn/Cu react with excess NH4OH - hence we can diff b/w them using Cu or Pb
The alkali + metal / metal oxide => learn general equations , you can balance on your own. But REMEMBER : with Al , water is present in equation ,ie. 2Al + 2NaOH + 2H2O -> 2NaAlO2 + 3H2
For practical chemistry :
Make a chart and label all gases in the 1st column. Write 2 tests for each and read through the remaining tests. Remember that H2S gives yellow paritcles of sulphur but SO2 doesnt ( with KMnO4/K2Cr2O7)
For compounds in general : Make a table with columns : Reaction / Precaution / Give reasons / Conditions / Collection
For HCl :
Do the preparation thoroughly. Read through physical properties with emphasis on the 2 experiments of HCl - heavier than air / fountain. Do the BACK SUCTION AND FUNNEL ARRANGEMENT thoroughly, it almost always comes - do the diagram, the reason for not using direct tube and reasons for using funnel + the definition of back suction. The physical properties of HCl acid - colour / odour / corrosive / BP - 109.8C - constant boiling mixture - All reactions are easy - common property of acids - do the thiosulphate reaction - The equations of Oxidising agent ( i had told in a prev post how to do it) and Aqua regia is important - TESTS are very important / just glance through uses.
For Ammonia - Do both preparation methods thoroughly and EMPHASISE on haber's process - reaction / conditions / give reasons / separation.
The physical properties - Colour / Non - poisonous / Fountain experiment / Lone Pair effect . Do the burning reactions with observations. Difference b/w Liquid ammonia and liquified ammonia. Basic nature and analytical is discussed already. The reducing property is important - do the CuO/PbO/Chlorine - excess/ deficient reaction with observation. The REFERENCE is important. TESTS are important.Glance through uses.
For Nitric Acid - Thoroughly do preparation ( in the chart I told you to make) .
Do decomposition / yellow colour of lab HNO3/ removal of brown tinge.
Learn all equations of Ostwald's process and only read reasons - won't be asked most probably.
Physical properties - Fuming / conc / dil HNO3 concentration - Odour / Constant boiling Mixture - 121 C 68% acid - 98% purified with conc. H2SO4 - Do effect of HNO3 on skin - xanthoproteic acid.
Dil HNO3 is a normal acid ( but slightly oxidising agent too) - Do equations only in syllabus and the Mg / Mn equation is important even though it is not in syllabus - Do passivity , and reason why HNO3 forms H2 with Mg/Mn
For inorganic compounds - only learn oxidised product - Tests are Very Important - especially brown ring - learn the equation and reasons. ( Learn eq the way I told you before)
Glance through uses.
H2SO4 - learn all equations / conditions for SO2 -> SO3 / read the give reasons.
Physical properties - Colour / Nature - hygroscopic and oily / BP - 338C Constant boiling mixture - Why acid is added to water and not water to acid / dil state = normal acid.
Conc state = oxidising agent : oxidises H2 to H2O and liberates SO2 in every reaction.
Conc state = non volatile nature : prep of HCl/HNO3
Conc state = Drying agent / Dehydrating agent : Drying HCl / HNO3 ; Dehydrating CuSO4.5H2O , Glucose , Sugar
Learn only syllabus equations and oxidised product of non-syllabus equations.
Learn tests for dil H2SO4 - BaCl2 and Pb(No3)2
conc H2SO4 - Cu / NaCl / NaNO3
For Organic Chemistry :
Lets talk about theory first :
Learn tetravalency / isomerism / catenation / homologous series - General formula of all series ( I will write them down below) / Alkyl grp / Functional grp / For nomenclature - read text book and preference chart (below) - practice with a lot of compounds - given behind Viraf / Learn trivial and IUPAC names of first 3 compounds of all homologous series - given in txt bk ( Write them down as a chart) / Hydrocarbons / Diff b/w saturated and unsaturated - with reasons.
General formulae ( For you to learn :)
Alkane - Cn H2n+2
Alkene - Cn H2n
Alkyne - Cn H2n-2
Alcohol - Cn H2n+1 OH
aldehydes - Cn H2n+1 CHO ( diff from txt bk)
acids - Cn H2n+1 COOH ( diff from txt bk)
alkyl halides - Cn H2n+1 - X ( X = halide = F/Cl/Br/I)
Ketones = Cx H2x+1 - CO - Cy H2y + 1 ( Diff from txt bk - x and y are integers, they can be same or diff)
Ether = Cx H2x+1 - O - Cy H2y + 1 ( Diff from txt bk - x and y are int , can be same/ diff)
For Compounds :
Do all reactions and conditions + uses
Equations :
Let start with alkanes.
You have to by heart the preparation, I can do nothing abt that
For the chemical properties,
It undergoes substitution
So some atoms are replaced. Its similar to simple displacement
So for chlorination, only 1Cl attaches to methane / ethane
So CH4 +Cl2 -∆---> CH3Cl + HCl
One H gets replaced by Cl and there is one Cl left, so HCl is the other product.
Do the same thing till you get CCl4
For oxidation, its really simple.
In excess air, CO2 + H2O are formed ( as excess air has lot of Oxygen)
In insufficient air , CO + H2O are formed ( as oxygen is limited)
In very limited air , C + H2O are formed
For the controlled slow oxidation, i.e. alkanes -> alcohols -> aldehydes -> acid
I have learnt it like this :starting product is alkane
Then Ol Al Oic
Alcohol, Aldehyde, Oic acid
Pyrolisis is just removsl of hydrogen. So remove hydrogen to form a substance
Methane forms ethyne and ethane forms ethene
For the Cu tube and 200C reaction, remember that alkanes form alcohol
For the MoO and 350-500C reaction,
The last letter of MoO is "O", so the last letter of product is also O, hence it is aldehyde. (hCHO)
Alkenes:
Learn equation for preparation
So in alkenes, the chemical reactions are just too simple
Whatever the reactants are, add them up to form 1 eq: addition product. It is same as direct combination
Remember thar whenever you add product, the double bond converts to single bond
Eg CH2=CH2 + H2 ---Ni 300C ----> CH3 - CH3
CH2= CH2 + HCl --> CH3 - CH2Cl
Make diagrams in question paper if you get confused, ie structural formulae to show breaking of bonds
Remember all tests Br test and KMnO4 test
Polymerisation, ozonolysis and oxidation reactions are out of syllabus
Ethyne : Learn preparation
The reactions are similar to ethene
In ethene, addition takes place in 1step as double breaks into single bond
In ethyne it is in two steps as triple breaks into double into single
Eg : C2H2+ H2---> C2H4
C2H4 + H2 ----> C2H6
Remember the difference between the end products of halogenation and halogen acids
One forms 1,2 dibromo
Other forms 1,1 di bromo ( formed with halogen acid)
Learn all tests, Br water, KMnO4, ammoniacal cuprous chloride and silver nitrate
Ethanol : learn preparation
The oxidation is same , forms CO2 and H2O
The K2Cr2O7 oxidation is same
Ol- Al - Oic
Learn Na equation, it forms Sodium ethoxide and H2 : C2H5ONa
Esterification is very important and it is reversible reaction
Learn the 2 equations with H2SO4
The 170C is prep of ethene
The 140C one is prep of diethylether
Acetic acid shows same properties as normal acids
Learn its prep
Esterification is imp
Do all tests, ester tests and wine red FeCl3 test
Thank You :) |
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