Sunday, December 30, 2007

IIT JEE 2008 Sample MCQs

1. Borax is :
(a) Sodium metaborate
(b) Sodium orthoborate
(c) Sodium tetraborate
(d) Sodium tetraborate decahydrate


2. The two compounds sulphato penta-ammine cobalt(III) bromide and sulphato penta-ammine cobalt(III) chloride are examples for:
(a) Linkage isomerism
(b) Ionisation isomerism
(c) Co-ordination isomerism
(d) No isomerism.

3. An alkene in reaction with hot acidified KMnO4 gives succinic acid. The alkene is
(a) 1-butene
(b) 2-butene
(c) 2-methylbutene
(d) cyclobutene

Monday, December 24, 2007

Application Questions Ch. 2 Gaseous, Liquid, and Solid States

1. to which of the following is Dalton's law of partial pressures not applicable?

a) H2 and He
b) NH3 and HCL
c) N2 and H2
d) N2 and O2

2. In silica (SiO2) each silicon atom is bonded to

a) two oxygen atoms
b) four oxygen atoms
c) one silicon and four oxygen atoms
d) octahedrally to six oxygen atoms

Application Questions Ch. 3 Atomic Structure

1. The quantum numbers of last electron in an atom are 4,0,0,1/2. the atomic number of the element would be:

a) 21
b) 20
c) 19,20,29,30
d) 19,20

Application Questions Ch. 4 Periodic Table

1. Which of the following pairs of elements have almost similar atomic radii?

a) Zr, Hf
b) Mo, W
c) Co, Ni
d) all of these

Application Questions Ch. 5 Bonding

Understand the following statements

1. CuSO4 has ionic, covalent and coordinate bonds
2. SO2 involves sp2 hybridization
3. HgCl2 and C2H2 are linear molecules
4. CH3+ has sp2 hybridization
5. SO2, NO2 and ClO2 are not linear while CO2 is linear.
6. NCO- has linear structure.
7. In ClO2- chlorine atom has sp3 hybridization
8. In OF2 oxygen atom will have sp3 hybridization.
9. N2O4 has covalent and coordinate bonds
10. Molecular oxygen has unpaired electrons.
11. NO3- has sp2 hybridization.
12. NO2+ has sp hybridization


MCQs

1. Which of the of following do not exhibit both ionic and covalent bond.
a) BaSo4
b) NH4Cl
c) Ca(NO3)2
d) HCl

2. Which of the following has maximum covalent character?
a) LiI
b) LiF
c) LiCl
d) LiBr

Application Questions Ch. 6 Energetics

1. If 10.0 g of a radioactive isotope has a half life of 10 hours, the half life of 4.0 g of the same substance is

a) 2.5 hrs
b) 5 hrs
c) 10 hrs
d) 40 hrs

Application Questions Ch. 7 Chemical Equilibria

1. which oneof the following acids is stronger?
a) boric acid ka = 5.881*10^(-10)
b) acetic acid ka = 1.8*10^(-5)
c) benzoic acid ka = 6.3*10^(-5)
d) hydrocyanic acid ka = 7.2*10^(-10)

Application Questions Ch. 8 Electrochemistry

1. Beryllium is placed abvoe magnesium in the electrochemical series. When beryllium dust is added to MgCl2 solution it will

a) have no effect
b) precipitate Mg metal
c) liberate Cl2
d) precipitate MgCl2

Application Questions Ch. 9 Solutions

1. a solution contains 8.84 g of H2SO4 in 10 ml and the density is 1.8 g/cc, the molality of the solution is

a) 12.55m
b) 6.20
c) 36.05
d) 9.85

Application Questions Ch. 10 Chemical Kinetics

1. A large increase in the rate of a reactin with increase in temperature is due to

a) increase in the number of collisions
b) increase in the number of activated collisions
c) decrease in mean free path
d) decrease in activation energy

App Questions Ch. 11. SURFACE CHEMISTRY

Application Questions - 12 Nuclear Chemistry

Application Questions - 13 Nonmetals

1. Which member of the group 13 does not exhibit the group valency in its compounds?
a) boron
b) aluminium
c) gallium
d) thallium

Application Questions - 14 Compounds of Metals

Application Questions - 15 Compounds of Nonmetals

1. which of the following leaves no risidue on heating?

a) Pb(NO3)2
b) NH4NO3
c) Cu (NO3)2
d) NaNO3

Application Questions - 16 Transition elements

1. Which of the foloowing has the maximum number of unpairded d-electrons

a) Zn
b) Fe^2+
c) Ni^3+
d) Cu^+

Application Questions - 17 Ores - Extraction

Application Questions - 18 Inorganic Chemistry Exercises

Application Questions - 19 Hybridization

Application Questions - 19 Isomerism

Application Questions - 19 Nomenclature

Application Questions - 20 Inductance - Resonance

Thursday, December 20, 2007

Application Questions - 21 Alkanes

Application Questions - 22 Alkenes

1. An alkene on treating with hot acidified KMnO4 gives 4-oxopentanoic acid. The alkene is
(a) pentene
(b) 2-pentene
(c) 1-methylcyclobutene
(d) 1,2-dimethylcyclopropene

2. The addition of Br2 to trans-2-butene produces
(a) (+)-2,3-dibromobutane
(b) (-)-2,3-dibromobutane
(c) rac-2,3-dibromobutane
(d) meso-2,3-dibromobutane

3. The treatment of propene with Cl-2 at 500-600 °C produces
(a) 1,2-dichloropropane
(b) allyl chloride
(c) 2,3-dichloropropene
(d) 1,3-dichloropropene

4. The electrophilic addition of 1,3-butadiene produces
(a) 1,2-addition product only
(b) 1,4-addition product
(c) both 1,2- and 1,4- addition products which are not at equilibrium with each other
(d) both 1,2- and 1,4-addition products which are at equilibrium with each other

Application Questions - 23 Alkynes

1. Which of the following is most acidic?

a) butane
b) 1-butene
c) 1-butyne
d) 2-butyne

2. Acetylene reacts with water in the presence of Hg^2+ and acidic medium to give
a) ethanal
b) ethanol
c) ethane
d) propanal

3. The compound which forms only acetaldehyde upon ozonolysis is:

a) Ethyne
b) Propene
c) 1-Butene
d) 2-Butene

4. The number of acidic hydrogen atoms in 1-butyne is

a) 1
b) 2
c) 3
d) 4

5. Which of the following can exhibit geometrical isomerism?

a) 2-butyne
b) 2-butene
c) 1-butene
d) 2-butanol

Application Questions - 24 Benzene

Application Questions - 25 Alcohols

Application Questions - 26 Alkyl and Aryl Halides

Application Questions - 27 Aldehydes and Ketones

Application Questions - 28 Carboxyic Acids

Application Questions - 29 Phenols

Application Questions - 30 Amines

Application Questions - 31 Carbohydrates

Application Questions - 32 Amino Acids and Peptides

Application Questions - 33 Polymers

Application Questions - 34.Organic chemistry Exercises

Monday, December 17, 2007

Past JEE Questions Introduction

A structure is created to post past JEE questions chapterwise for easy reference.

Candidates need to develop deep understanding of the concepts and procedures covered in the texts and then develop the ability to apply those concepts and procedures to the types of problems and questions posed in JEE examinations.

So candidates have to keep the textbook knowledge on right and JEE questions on left and keep turning the head in both directions repeatedly so that they are adequately prepared for facing the actual JEE examination.

Past JEE Questions Ch.1

JEE Question 2007 paper I Linked Comprehension




Chemical reactions involve interaction of atoms and molecules. A large number of atoms/molecules (approximately 6.023 ×10^23 ) are present in a few grams of any chemical compound varying with their atomic/molecular masses. To handle such large numbers conveniently, the mole concept was introduced. This concept has implications in diverse areas such as analytical chemistry, biochemistry electrochemistry and radiochemistry. The following example illustrates a typical case, involving
chemical/electrochemical reaction, which requires a clear understanding of the mole concept.

A 4.0 molar aqueous solution NaCl is prepared and 500 mL of this solution is electrolysed. This leads to the evolution of chlorine gas at one of the electrodes (atomic mass : Na = 23, Hg = 200;1 Faraday = 96500 coulombs).

1. The total number of moles of chlorine gas evolved is
(A) 0.5
(B) 1.0
(C) 2.0
(D) 3.0

Answer: B


2. If the cathode is a Hg electrode, the maximum weight (g) of amalgam formed from this solution is

(A) 200
(B) 225
(C) 400
(D) 446

Answer: D

In presence of Hg cathode sodium ion will discharge in place of hydrogen gas due to over voltage in the form of amalgams.

Weight of amalgam = 2 × (23 + 200) = 446 g

3. The total charge (coulombs) required for compete electrolysis is

(A) 24125
(B) 48250
(C) 96500
(D) 193000

Answer: D

Total charge = 2 × 96500 = 193000 C

This question is better answered after studying the electro chemistry chapter.
--------------------------

JEE Question 2007 paper II

Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenylamine as indicator. The number of moles of Mohr’s salt required per mole of dichromate is

(A) 3
(B) 4
(C) 5
(D) 6

Answer D

From Compounds of metals chapter
Mohr's salt is a double salt. FeSO-4.(NH-4)-2SO-4.6H-2O
It is obtained by mixing freshly prepared ferrous sulphate in solution with equal molar amounts of ammonium sulphate and then allow the solution to crystallize.

Past JEE Questions Ch.2

JEE Question 2007 paper II
Matrix matching


Match the chemical system/units cells mentioned in column I with their characteristic features mentioned in column II. Indicate your answer by darkening the appropriate bubbles of the 4 × 4 matrix given in the ORS.

Column I------------------------- Column II
(A)simple cubic and ---------(p)have these cell
face-centred cubic------------parameters a = b = c and
------------------------------ α =β = γ

(B)cubic and rhombohedral-- (q) are two crystal systems
(C) cubic and tetragonal (r) Have only two
-----------------------------crystallographic angles of
------------------------------90°
(D) hexagonal and monoaclinic --(s) Belong to same
------------------------------------crystal system


Solution
A – p, s
B – p, q
C – q
D – r, q
----------------------------------

Past JEE Questions Ch.3 Atomic Structure

JEE Question 2007 paper II

Statement - 1

Band gap in germanium is small.

Because

Statement - 2

The energy spread of each germanium atomic energy level is infinitesimally small.

(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is NOT a correct explanation for Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True

Answer C

Past JEE Questions Ch.4

Past JEE Questions Ch.5 Bonding and Molecular Structure

1991
The linear structure is not assumed by
a) SnCl2
b) CS2
c) NO2+
d) HCN

Answer a

1992
The molecule that will have no dipole meet is:
a) 2,2-dimethyl propene
b) Trans 2-pentene
c) cis-3-hexane
d)2,2,3,3,-tetramethylbutane

ans: d

1993

Which of the following has zero dipole moment?
a) CLF
b) PCl3
c) SiF4
d) CFCl3

ans: c

1995

Which is most ionic?
a) P2O5
b) MnO
c) CrO3
d) Mn2O7

b


1996
The number and type of bonds between two carbon atoms in calcium carbide are

a) one σ , one π
b) one σ, two π
c) two σ , one π
d) one σ, 1½ Ï€

Ans: b

1997
Which one of the following compounds has sp2 hybridization
a) CO2
b) SO2
c) N2O
d) CO

ans: b

1998
The geometry and type of hybrid orbital present about the central atom in BF3 is

a) linear, sp
b) trigonal planar, sp^2
c) tetrahedral, sp^3
d) pyramidal, sp^3

ans: b

1999
The geometry of H2S and its dipole moment are:
a) angular and non-zero
b) angular and zero
c) linear and non-zero
d) linear and zero


2000 screening
Molecular shapes of SF4, CF4, and XeF4 are
a) the same with 2,0,1 lone pairs of electrons respectively
b) the same with 1,1,1,lone pairs of electrons respectively
c) different with 0,1,and 2 lone pairs of electrons respectively
d) different with 1,0, and 2 lone pairs of electrons respectively

ans: d

2001 screening
The correct order of bybridization of the central atom in the following species: NH3, [PtCl4]2-, PCl5 and BCl3 is

a) dsp^2, dsp^3, sp^2, and sp^3
b) sp^3, dsp^2,dsp^3,sp^2
c) dsp^3,sp^2,sp^3,dsp^3
d) dsp^2,sp^3,sp^2,dsp^3

ans: b

Among the following, the molecule with the highest dipole moment is:

(A) CH-3Cl (B) CH-2Cl-2
(C) CHCl-3 (D) CCl-4

answer A
----------------------------

JEE Question 2007 paper I

The percentage of p-character in the orbitals forming P–P bonds in 4 P is
(A) 25
(B) 33
(C) 50
(D) 75
Solution: (D)

Phosphorous will show sp^3 hybridisation having 75% p-character.
--------
JEE Question 2007 paper I

Statement - 1

Boron always forms covalent bond

Because

Statement - 2

The small size of B3^+ favours formation of covalent bond.

(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True

Answer: A

-------------------------------

JEE Question paper II 2007

Among the following metal carbonyls, the C — O bond order is lowest in
(A) [Mn(CO)-6]^+

(B) [Fe(CO)-5]
(C) [Cr(CO)-6]
(D) [V(CO)-6]^-


answer: B
-----------------

JEE 2006

If the bond length of CO bond in carbon monoxide is 1.128 A,
then what is the value of CO bond length in Fe(CO)-5?
(A) 1.15 A
(B) 1.128 A
(C) 1.72 A
(D) 1.118 A


Answer: (A)
----------------------

Past JEE Questions Ch.6

JEE Question 2007 paper II

For the process (water becoming steam) H-2O(l)(1 bar, 373 K) --> H-2O(g)(1 bar, 373 K), the correct set of thermodynamic parameters is

(A) ∆G=0,∆S= + ve
(B)∆G=0,∆S= -ve
(C)∆G=+ve,∆S=0
(D)∆G=-ve, ∆S= + ve

Solution: A


The answer is A because, because at 100 degree C, the steam and water mixture is at equilibrium. Hence ΔG = 0(G = H - TS), and ΔS is positive. Why? when liquid becomes gas, there is more disorder. More entropy.
--------------

Past JEE Questions Ch.7 CHEMICAL EQUILIBRIA

JEE Question 2007 Paper II

23. Consider a reaction aG+bH--> Products. When concentration of both the reactants G and H is doubled, the rate increases by eight times. However, when concentration of G is doubled keeping the concentration of H fixed, the rate is doubled. The overall order of the reaction is
(A) 0
(B) 1
(C) 2
(D) 3

Solution: D

This is a question of chapter chemical kinetics.
Reason: When G alone is doubled, rate is doubled. That is the exponent of [G] is one in rate law. When both are doubled, rate increases by 8 times, telling us that exponent of [H] is 2 in rate law. So overall order of reaction is sum of the two exponents that is 3.
--------------------

Past JEE Questions Ch.8 ELECTROCHEMISTRY

Past JEE Questions Ch.9 SOLUTIONS

JEE Question 2007 paper I

When 20 g of naphthoic acid (C-11H-8O-2) is dissolved in 50 g of benzene (K-f = 1.72 K kg mol^-1), a freezing point depression of 2 K is observed. The van’t Hoff factor (i) is


(A) 0.5
(B) 1
(C) 2
(D) 3

Answer: A

Van't Hoff factor = Normal Molar Mass/Observed Molar mass

Observed Molar Mass M-B = K-f*1000*W-B/(W-A*ΔT-f)

K-f = Molal depression constant
W-A = weight of solvent
W-B = weight of solute
ΔT-f = depression in freezing point.

In the problem Normal Molar mass = 172
Observe molar mass = 1.72*1000*20/50*2 = 17.2*20 = 172*2

Van't Hoff factor =172/172*2 = 0.5

Ref: Dr. Jauhar's book unit 3: solutions.

Past JEE Questions Ch.10 CHEMICAL KINETICS

Past JEE Questions Ch.11 SURFACE CHEMISTRY

JEE Question 2007 Paper I

Statement - 1
Micelles are formed by surfactant molecules above the critical micellar concentration (CMC)

Because

Statement - 2

The conductivity of a solution having surfactant molecules decreases sharply at the CMC.

(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for
statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for
Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True

Correct choice: B
-----

Past JEE Questions Ch.12 NUCLEAR CHEMISTRY

1996
(27,13) Al is a stable isotope. (29,13) Al is expected to disintegrate by
a) α emission
b) β emission
c) positron emission
d) proton emission

1998

Loss of β particle is equivalent to
a) increase of one proton only
b) decrease of one neutron only
c) both of (a) and (b)
d) none of these

1998

Decrease in atomic number is observed during

a) α emission
b) β emission
c) positron emission
d) electron emission

1991
The nucleus resulting from (238, 92) U after successive emission of two α particles and four β particles is

a) (230,90) Th
b) 230,94 Pu
c) 230,88 Ra
d) 230,92 U

1991

The number of neutrons accompanying the formation of 139,54 Xe and 94,38 Sr from the absorption of slow neutron by 235,92 U followed by nuclear fission is

a) 0
b) 2
c) 1
d) 3

Past JEE Questions Ch.13 Non-Metal Elements

JEE question

Statement - 1
Boron always forms covalent bond

Because
Statement - 2

The small size of B^3+favours formation of covalent bond.

(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True

answer A
This point is explicitly given in Jauhar's book
----------------------

JEE Question 2007 Paper I Linked Comprehension

The noble gases have closed-shell electronic configuration and are monoatomic gases under normal conditions. The low boiling points of the lighter noble gases are due to weak dispersion forces between the atoms and the absence of other interatomic interactions. The direct reaction of xenon with fluorine leads to a series of compounds with oxidation numbers +2, +4 and + 6. 4 XeF reacts violently with water to give XeO-3 . The compounds of xenon exhibit rich stereochemistry and their geometries can be deduced considering the total number of electron pairs in
the valence shell.


1. Argon is used in arc welding because of its

(A) low reactivity with metal
(B) ability to lower the melting point of metal
(C) flammability
(D) high calorific value

Solution: A

Argon provides inert atmosphere in welding due to low reactivity with metal.

2. The structure of XeO-3 is

(A) linear
(B) planar
(C) pyramidal
(D) T-shaped

Coorect choice: C

3. XeF-4 and XeF-6 are expected to be

(A) oxidizing
(B) reducing
(C) unreactive
(D) strong basic

Answer: A
----------------------------

Past JEE Questions Ch.14 COMPOUNDS OF METALS

JEE Question 2007 paper II

Statement - 1

Alkali metals dissolve in liquid ammonia to give blue solutions.

Because

Statement - 2

Alkali metals in liquid ammonia give solvated species of the type [M(NH-3)-n]^+ (M= alkali metals.

(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for
statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for
Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True

Solution: B


Blue colour appears due to solvated electrons in liquid ammonia.

Past JEE Questions Ch.15 Compounds of Non-metals

Past JEE Questions Ch.16

Past JEE Questions Ch.17 Ores/Minerals and Extractive Metallury

-----------------------
JEE Question 2007 Paper I

Extraction of zinc from zinc blende is achieved by
(A) electrolytic reduction
(B) roasting followed by reduction with carbon
(C) roasting followed by reduction with another metal
(D) roasting followed by self-reduction

Answer: B
Roasting followed by reduction with carbon.
---------------------------

Past JEE Questions Ch.18 Exercises in Inorganic Chemistry

JEE Question 2007 paper II

A solution of a metal ion when treated with KI gives a red precipitate which dissolves in excess KI to give a colourless solution. Moreover, the solution of metal ion on treatment with a solution of cobalt(II) thiocyanate give rise to a deep blue crystalline precipitate. The metal ion is


(A) Pb2^+
(B) Hg2^+
(C) Cu2^+
(D) Co2^+

Answer: B

Past JEE Questions Ch.19 Hybridization, Isomerism, and Nomenclature

JEE Question 2007 Paper I

The number of structural isomers for C-6H-14 is

(A) 3
(B) 4
(C) 5
(D) 6

Answer: C



--------------------------
JEE question 2007

STATEMENT-1: Molecules that are not superimposable on their mirror images are chiral.

Because

STATEMENT-2: All chiral molecules have chiral centres.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for
Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True

Solution C
----------------------------

JEE Question 2007 Paper II

The number of stereoisomers obtained by bromination of trans-2 butene is

(A) 1
(B) 2
(C) 3
(D) 4

Answer: A

Meso compound is the output.
---------------------------

Past JEE Questions Ch.20 Inductance - Resonance

Past JEE Questions Ch.21 Alkanes

Past JEE Questions Ch.22 Alkenes

1984

Baeyer's reagent is
a) alkaline potassium permanganate solution
b) acidified potassium permanganate solution
c) neutral potassium permanganate solution
d) acqueous bromine solution

1985.

anti-markonikov addition of HBr is not observed in
a) propene
b) butene
c) 2-butene
d) 2-pentene

1986
Dipole moment is shown by

a) 1,4 dichlorobenzene
b) cis-1,2-dichloroethene
c) trans-1,2-dichloroethene
d) 1,2-dichloro-2-pentene

Answer b and d

1987

4. of the following compounds, whihc will have a zero dipole moment

a) 1,1 dichloroethylene
b) cis-1,2-dichlorethylene
c) trans-1,2-dichloroethylene
d) none of these compounds

answer c

1991

5.1-chlorobutane on reaction with alcoholic potash gives
a) 1-butene
b) 1-butanol
c) 2-butene
d) 2-butanol

answer a

1992

6. The molecules that will have dipole moment are

a) 2,2-dimethylpropane
b) trans-2-pentene
c) cis-3-hexene
d) 2,2,3,3,-tetrametylbutane

answer b and c.

1993

Which of the following has the smallest heat of hydrogenation per mole?
a) 1-butene
b) trans-2-butene
c) cis-2-butene
d) 1,3-butadiene

answer d

1998
Which of the following compounds will show geometric isomerism?
a) 2-Butene
b) Propene
c) 1-Phenylpropene
d) 2-Methyl-2-butene

2000

Which of the following compounds will exhibit geometric isomerism?
a) 1-phenyl-2-butene
b) 3-phenyl-1-butene
c) 2-phenyl-1-butene
d) 1,1-Diphenyl-1-propene


JEE Question 2007 paper II

Cyclohexene on ozonolysis followed by reaction with zinc dust and water gives compound E. Compound E on further treatment with aqueous KOH yields compound F. Compound F is

Options given as pictures

Past JEE Questions Ch.23

1998
Among the following the strongest acid is

a) HC≡CH
b) C6H6
c) C2H6
d) CH3OH

JEE Questions Ch.24

JEE Questions Ch.25 Alcohols

---------------------
JEE 2006

(I) 1,2-dihydroxy benzene (II) 1,3-dihydroxy benzene
(III) 1,4-dihydroxy benzene (IV) Hydroxy benzene

The increasing order of boiling points of above mentioned alcohols is

(A) I < II < III < IV (B) I < II < IV < III
(C) IV < I < II < III (D) IV < II < I < III

Solution (C)
------------------------

JEE Questions Ch.26

JEE Questions Ch.27 Aldehydes, Ketones

1. How will you convert
i) Acetone to 2-methyl-2-propanol
ii) Ethanal to 2-hydroxy-3-butenoic acid 1990

2. CH3COCH3-----base,catalyst---> ? -----acid,catalyst--> ? 1998

3.Benzene with one H substituted by CHO-----------K2Cr2O7, Conc.H2SO4--->?----PCl5--?----NH3----> ?-------P2O5---> ? 1986

4. Write the IUPAC name of CH2=CHCHO 1993

5. A ketone (A) which undergoes haloform reaction gives compound B on reduction. B on heating with conc. H2SO4 gives a compound (C) which forms monozonide(D). D on hydrolysis in the presence of zinc dust gives only acetaldehyde. Identify A,B,C,D. Write down the reactions involved. 1989

6. An alkene (A) on ozonolysis gives acetone and an aldehyde. The aldehyde is easily oxidized to an acid (B). When (B) is treated with bromine in the presence of phosphorus, it yields compound (C) which on hydrolysis gives an hydroxy acid (D). This acid can alos be obtained from acetone hy the reaction with hydrogen cyanide followed by hydrolysis. Identify the compounds A,B,C and D. 1991

7. An aldehyde, A (C11H8O) which does not undergo self aldol condensation gives benzaldehyde and two moles of B on ozonolysis. compound B on oxidation with silver ion gives oxalic acid. Idenity the compounds A and B. 1997

8. An organic compound A, C6H10O, on reaction with CH3MgBr followed by acid treatment gives compound B. The compound B on ozonolysis gives compound C, which in presence of a base gives 1-acetyl cyclopentene, D. The compound B on reaction with HBr gives compound E. Write structures of A,B,C,D and E. Show how D is formed from C. 2000

9. C6H5CHO + CH3COOC2H5-----NaOC2H5 in C2H5OH & heat------>? 1995

10. How many asymmetric carbon atoms are created during the complete reduction of benzil (PhCOCOPh) with LiAH4. Also write the number of possible stereoisomers of the product. 1997

11. Acetophenone on reaction with hydroxylamine hydrochloride can produce tow isomeric oximes. Write structures of the oximes. 1997

12. An alkene A(C16H16) on ozonolysis gives only one product B (C8H8O). Compound B on reaction with NaOH/I2 yields sodium benzoate. Compound B reacts with KOH/NH2NH2 yielding a hydrocarbon (C) C8h10. Write the structure of compound B and C. Based on this information two isomeric structures can be proposed for alkene A. Write their structures and identify the isomer which on catalytic hydrogenation (H2/Pd-C) gives a recemic mixture. 2001

13. The formation of cyanohydrin from ketone is an example of

a) Electrophyllic addition
b) Nucleophilic addition
c) Necleophilic substitution
d) Electrophilic substitution 1990

JEE Questions Ch.28 Carboxylic acids

1. Among the following the strongest acid is

a) HC≡HC
b0 C6H6
c) C2H6
d) CH3OH

1999

2 When propionic acid is treated with acqueous sodium bicarbonate CO2 is liberated. The C of CO2 comes from
a) methyl group
b) carboxylic group
c) Methylene group
d) bicarbonate

1999

3) Which of the following carboxylic acids undergoes decarboxylation easily

1995

4. Benzoyl chloride is prepared from benzoic acid by

a) Cl2, hv
b) SO2Cl2
c) SOCl2
d) Cl2, H2O

2000

5. Identify the order of boiling points

1. CH3CH2CH2CH2 OH
2. CH3CH2CH2CHO
3. CH3CH2CH2COOH

Screening 2002
screening 2002

JEE Questions Ch.29

Past JEE Questions Ch.30 Amines

1. How will you convert 4-nitroaniline to 1,2,3-tribromobenzene 1990
2. How will you synthesis benzamide from nitrobenzene? 1994
3. How do you prepare m-bromoiodo benzene from benzene? 1997
4. Write the structure of products of the following reaction
CH3CONHC6H5 ----Br2,Fe--->
5. How will you bring about conversion of analine to benzylamine?
6. Arrange the following in the decreasing order of basic character:

a) Methylamine, dimethylamine, aniline, N-methylaniline
b) CH3CH2CH2NH2, HO(CH2)3NH2, HO(CH2)2NH2
c) CH2=CHCH2NH2, CH3CH2CH2NH2, CH≡CCH2NH2
7. p-chloroaniline and anilinium hydrochlordie can be distinguished by
a) sanmeyer's reaction
b) NaHCO3
c)AgNO3
d) Carbylamine test 1998

8. Among the following the strongest base is

a) C6H5NH2
b) p-NO2-C6H4NH2
c) m-NO2-C6H4NH2
d) C6H5CH2NH2 2000

9. In reaction of p-chlorotoluene with KNH2 in liquid NH3, the major product is

a) 0-toluidine
b) m-toluidine
c) p-toluidine
d) p-chloroaniline 1997

JEE Questions Ch.31

JEE Questions Ch.32

JEE Questions Ch.33

JEE Questions Ch.34 Exercises in Organic Chemistry

Thursday, December 6, 2007

Blog Status 7-12-2007

I am only posting basic questions that help in clarifying basics of the topic.After I complete posting basic questions in all the chapters and posting answers to them, I shall attempt more varieties. As this blog posting is part of my effort to provide limited help to a person with a formal coaching with professional faculty, the pressure on me is limited and I take up activity only when I find some time.

Sunday, December 2, 2007

2007 JEE questions pattern

Topic -------------No. of questions


States of Matter------------1
-Solid state ---------------1

Atomic Structure & ---------6
Chemical Bonding

Dilute Solutions------------1

Thermodynamics--------------2

Chemical kinetics-----------1

Redox reaction--------------2

Surface Chemistry----------1

Electrochemistry-----------5

Nuclear chemistry----------1

Coordination Compounds-----2

P Block Elements-----------4

S block elements----------1


Metallurgy-----------------1

Basic Principles in
Organic Chemistry----------2


Hydrocarbons---------------2


Biomolecules / Polymers----2

Qualitative analysis------1



Aldehyde and ketone-------1



Stereo chemistry----------2



Purification and ---------1
characterization of
organic compounds



Phenols------------------3



Organic reactions--------1

Total questions---------44

Blog Status 2-12- 2007

Today, I posted questions in chemical kinetics chapter.

iit-jee-chemistry-ps.blogspot.com/2007/10/iit-jee-chemistry-questions-ch10.html