1. The document provides guidance for students taking their board practical exam, outlining 52 important points to remember and topics to study. 2. Students are instructed to show calculations for standard solutions, write balanced equations, describe procedures, record observations, and state results clearly in their exam. 3. The viva questions section lists over 40 topics that may be asked about in the oral exam, including theory, tests, reactions, and applications. Students are told to thoroughly learn the objectives, equations, and inferences related to these topics.

1. Dear students
Few pointers for the board practical exam .
Ensure to write the following
1. Aim
2. Molarity equation to calculate mass of oxalic acid / Mohr salt to prepare standard
soln ( this must be done within the first 5 minutes of writing time and shown to the
external examiner. )
3. Formula of mohr's salt /oxalic acid also to be written
4. Ionic equation (both oxidation and reduction half)
5. Brief procedure as below
Burette solution
Solution in conical flask - (Mention 2M dil. H2SO4 in pipette solution) + heat
the solution to 600 C for increasing the speed of the reaction for oxalic acid.
Indicator – KMnO4 – Self indicator
End point – (Initial to final colour)
6. Tabular column for observation .
7. Mention concordant value with unit below the column.
8. Calculation of molarity and strength
9. Final result with units of molarity and strength .
10.For organic and inorganic analysis one preliminary and two confirmatory tests for
each radical must be written. There are 16 experiments in the sample procedure
of every salt.
11.Result statement of organic analysis /biomolecules must be clear.
12.Ensure to mention the result clearly as cation anion and the salt .
13.QUICK IDENTIFICATION OF FUNCTIONAL GROUP:
Carboxylic acid – vinegar smell
Alcohol - Alcohol smell
Ketone – Nail polish smell
Aldehyde - Tollens test
Phenol – Light pink crystal
Amine – Light brown solution
VIVA QUESTIONS
1. Learn viva questions from comprehensive practical chemistry and also from
academic window .
2. Theory associated with the following tests should be thoroughly learnt for viva
with equations
Ester test
Dye test for amines,carbylamine test and Hinsberg test
Confirmatory tests of sulphates
Fehlings and Tollens test
Resonance in phenol and aniline
Brown ring test- Brown ring formula : [Fe(H2O)5(NO)]SO4
Formula of Nessler’s reagent

2. Dinitro phenyl hydrazine
Lime water test
Common ion effect and so on....
3. The objective , application and inference of your project must also be learnt for
the viva .
4. Why FeSO4 can't be used instead of Mohr salt for titration ?
FeSO4 easily oxidized.
5. Why KMnO4 cannot be used as primary std ?
It cannot be obtained in very pure form,It readily reacts with any traces of
organic material or any other reducing substance in water
6. Why is K2MnO4 is green?
7. Why is CuSO4 .5H20 is blue?
In hydrated CuSO4 the water molecules surrounding the Central metal (Cu)
function as ligands which bring d-d transition and hence emits blue colour in
visible region due which hydrated CuSO4 appears blue and as anhydrous CuSO4
doesn't have any water of crystallisation hence remains white in colour.
8. Describe autocatalysis in permanganometry .
When potassium permanganate undergoes a reaction with acidified oxalate
solution,the rate of the reaction is initially slow.It slowly increases in rate due to
the formation of Mn2+
ions:
The Mn2+
acts as a homogeneous catalyst because it is easily oxidised to Mn3+
by the MnO4
-
ions and then reduced back to Mn2+
ions by the C2O4
2-
ions.
9. Why Mg(OH)2 is a better antacid than NaHCO3?
Magnesium hydroxide is a better antacid because being insoluble it does not
allow the PH to increase above neutral . Hydrogen carbonate being soluble , its
excess can make the stomach alkaline and trigger the production of
even more acid.
10.Project applications
11.Why is NH4Cl added along with NH4OH during salt analysis for gp 3?
Due to common ion effect (NH4
+
ions), NH4Cl reduces the ionisation of NH4OH.
Then hydroxides of III group only (but not of those of IV group) are precipitated.
12.Structure of aspirin and it's difference in activity from an antihistamine .
Aspirin is in a group of drugs called salicylates (sa-LIS-il-ates). It works by
reducing substances in the body that cause pain, fever, and inflammation.
Antihistamine that reduces the effects of natural chemical histamine in the body.
Histamine can produce symptoms of sneezing, itching, watery eyes, and runny
nose.
13.Role of H2SO4 in esterification
Dehydrating agent and catalyst.
14.Role of heating in reaction.
Increase in K.E which further increases the rate

3. 15.Name of gases evolved in test for nitrate.
NO2 and Ammonium Chloride
16.why does the lime water turns colourless after passing CO2 for long time?
Forms calcium bicarbonate which is soluble.
17.Role of Cu chips in Nitrate test
Copper chips reduces nitrates to reddish brown NO2 gas.
18.Why is HCl not used to create acidic media in permanganometry ?
HCl oxidized to Cl2
19.Why KMnO4 is coloured?
Potassium permanganate(KMnO4) is colored because it absorbs light in the
visible range of the electromagnetic spectrum. The permanganate ion is the
source of the color, as a ligand-to-metal charge transfer takes place between
the oxygen's p orbitals and the empty d-orbitals on the metal. This charge
transfer takes place when a photon of light is absorbed, which leads to the
purple color of the compound.
20.How to differentiate organic functional groups?
21.Tollens and Fehlings equation
22.Why brown colour developes during permanganometry?
Insufficient quantity of dil.H2SO4.[Formation of MnO2 due to incomplete
oxidation of KMnO4]
23.Azo dye equation
24.Why aromatic compounds burn with sooty flame?
Carbon ratio compared to H is high ,so soots deposit when burns with insufficient
oxygen.
25.Why Mg white ppt scratched?
surface tension of supersaturated liquid breaks and recrystallization occurs.
26.Identification of oxidizing and reducing agent from ionic equation.
27.Role of H2SO4in paper ball test.
Paper, being derived from living matter contains Carbon in it. Carbon reduces
Nitrogen in Nitrate(+5 oxidation state) to Nitrogen Dioxide ( +4 O.S). Hence the
characteristics brown fumes of Nitrogen dioxide are produced and it helps in
Identification of NO3
-
ANION.
28.Equation for lyophobic [Fe(OH)3 preparation
29.Factors affecting rate of reaction
30.What is the catalyst in permanganometric titration?
31.Equation for nesslers reagent with ammonia. [Millon’s base]

4. 32.Difference between single and double salt.
A single salt has one cation and one anion. A double salt has two cations and
two anions. A double salt can be prepared by the crystallisation of a solution of
two single salts.
33.Difference between double and complex salt.
34.Why only con. H2SO4 is used for permanaganometry and not HCl or HNO3?
(HCl oxidises to Cl2,HNO3 as oxidizing agent)
35.Why conical flask is used in titration?
To avoid spilling and hence measurement is accurate.
36.Structure of KMnO4 and K2MnO4 : dichromate and chromate
37.Why we use dry test tube for salt with con. H2SO4 tests?
Con. H2SO4 dehydrates instead of expelling gases.
38.Why Zn resists flame test?
d10 configuration
39.Why Mg does not answer flame test?
Due to small size of magnesium and also beryllium, ionization energies are high
and not available in bunsen flame.So no excitation of electron takes place and no
flame test .
40.Why KMnO4 to be added dropwise in oxalic acid titration?
This is because the concentration is quite large. When you start the titration, the
dark purple KMnO is slowly added into the sample you are titrating. Under some
heat and acidic conditions, this will cause the Mn which is in 7+ oxidation state in
the permanganate to reduce into 2+ state as it reacts with the sample.
41.What is denatured spirit?
Denatured alcohol, also called methylated spirit (in Australia, New Zealand,
South Africa and the United Kingdom) or denatured rectifiedspirit, is ethanol that
has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to
discourage recreational consumption.

5. 42.
43.
Why is violet colour obtained in the neutral ferric chloride test?
Phenols form a violet complex with Fe(III)+, which is intensely colored.
44.Why HCl is not used in Permanganometry?
KMnO4 is a very strong oxidizing agent and it can oxidize HCl to liberate chlorine
gas, and some amount of KMnO4 is utilized for such oxidation and hence results
in volumetric error.therefore HCl cannot be used to acidify potassium
permanganate solution in volumetric analysis
45.why 20 ml 2M H2SO4 is used in titration?
Sulphuric Acid (H2SO4) is used in the redox titration process because it provides
the H(+) ions necessary for the reaction to occur more quickly whilst the
sulphate(-) ions barely react during the reaction. ... Actually, excess acid is
required since H+H+ is consumed during the reaction (8 mol H+H+ per 1 mol
MnO−4MnO4−).
46.Why is mohr salt not heated during titration?
Mohr’s salt is a very strong reducing agent. It reduces KMnO4 to Mn2+ at room
temperature itself. Therefore it is not heated.

6. 47.Why Mohr salt is called double salt?
48.When we titrate oxalic acid with a KMnO4 solution, it gets pink with the first drop
of KMnO4 from the burette, why is that?
When you are adding the very first drop of KMnO4 in oxalic acid solution, the
reaction runs on its own, i.e., uncatalysed. Therefore, you observe the colour
disappearing slowly.
After few drops have been added, the formation of Mn2+ ion makes the reaction
autocatalytic (Mn+2 acts as a catalyst).
49.What happens if dil.H2SO4 is not used?
KMnO4 acts as a good oxidising agent in acidic medium. If acid is not used
KMnO4 may be oxidised to MnO2 giving a brown precipitate.
50.Why K2Cr2O7 cannot be used as self indicator?
it can’t be used as a self indicator like KMnO4. This is because its reduction
product (Cr3+) is green which hinders in the visual detection of end point by
observing dichromate colour. Thus an another indicator is must in this titration.
51.Chemistry of blue lake formation in aluminium:
As soon as the solution becomes alkaline, blue floating precipitate is obtained.
Then the blue litmus solution is adsorbed on this aluminium hydroxide. This is
the Principle for this test, Aluminium hydroxide is a good adsorbent, and
therefore it adsorbs the blue litmus solution and gives this blue lake test.

7. 52.Magneson reagent is the indicator used to determine the presence of
magnesium element in the solution. It is an azo dye which functions as the spot
test reagent and forms a blue lake when reacted with in basic solution.
chemical name for this reagent is 4-(4-Nitrophenylazo) resorcinol.