IIT JEEE Chemistry - 1990

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IIT JEE - Past papers:

IIT JEE - Past papers CHEMISTRY- UNSOLVED PAPER – I990

SECTION – I:

SECTION – I Single Correct Answer Type This section contains 10 multiple choice questions. Each question has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct.

Problem:

01 Chlorination of toluene in the presence of light and heat followed by treatment with aqueous NaOH gives O-Cresol P-Cresol 2, 4 Dihydroxytoluene Benzoic acid Problem

Problem :

Problem 02 Amongst the following, the most basic compound is Benzylamine Aniline Acetanilide P- Nitroaniline

Problem:

Problem 03 The density of neon will be highest at STP , 2 atm , 1 atm , 2 atm

Problem:

Problem 04 The oxidation number of phosphorus is Ba is +3 +2 +1 -1

Problem:

Problem 05 The embolic from of acetone contains 9 sigma bonds, 1 pi bond and 2 lone pairs 8 sigma bonds, 2 pi bond and 2 lone pairs 10 sigma bonds, 1 pi bond and 1 lone pairs 9 sigma bonds, 2 pi bond and 1 lone pairs

Problem:

Problem 06 The freezing point of equimolal aqueous solutions will be highest for a . (aniline hydrochloride) b. c. d. (glucose)

Problem:

Problem 07 Amongst the following elements (whose electronic configurations are given below), the one having the highest ionization energy is a. b. c. d.

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Problem 08 The formation of cyanohydrin from a ketone is an example of Electrophonic addition Nucleophilic addition Nucleophilic substitution Electrophonic substitution

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Problem 09 Amongst the following hydroxides, the one which has the lowest value of at ordinary temperature (about 25 0 C) is a. b. c. d.

Problem:

Problem 10 The rate of diffusion of methane at a given temperature is twice that of gas X. The molecular weight of X is 64.0 32.0 4.0 8.0

SECTION – II:

SECTION – II Multiple Answer Type There are five parts in this equation. Each part has one or more than one correct answers. Indicate all correct answers for each part by writing the corresponding letters from (a), (b), (c), (d) in the answer book:

Problem:

01 Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl halides due to The formation of less stable carbonium ion Resonance stabilization Longer carbon-halogen bond The inductive effect Sp2 hybridized carbon attached to the halogen Problem

Problem :

Problem 02 The compounds used as refrigerant are a. b. c. d. e.

Problem:

Problem 03 When zeolite , which is hydrated sodium aluminum silicate, is treated with hard water the sodium ions are exchanged with H+ ions b. Ions c. ions Ions e. ions

Problem:

Problem 04 The aqueous solutions of the following salts will be colored in the case of a. b. c. d. e. Potash alum

Problem:

Problem 05 Of the following, the metals that cannot be obtained by electrolysis of the aqueous solution of their salts are Ag Mg Cu Al Cr

SECTION – III:

SECTION – III Fill in the blanks Read the following statements carefully. Indicate the subdivision number and write the matter corresponding to the blanks strictly in the order they appear in the statement

Problem:

01 The shape of [OH3] + is _______________. Problem

Problem :

Problem 02 The valence atomic orditals on C in silver acetylide is _____________ hybridized.

Problem:

Problem 03 The basicity of phosphorous acid is _________________.

Problem:

Problem 04 Phenol is acidic because of resonance stabilization of its conjugate base, namely, _______________.

Problem:

Problem 05 Fehling’s solution ‘A’ consists of an aqueous solution of copper sulphate , while Fehling’s solution ‘B’ consists of an alkaline solution of ______________.

SECTION – IV:

SECTION – IV True of False This question contains five statements, each of which is either true of false. Indicate your choice of the answer in the answer-book by writing TRUE or FALSE for each statement.

Problem:

01 The presence of polar bonds in a polyatomic molecule suggests that the molecule has non-zero dipole moment. Problem

Problem :

Problem 02 2, 3, 4-Thrichloropentane has three asymmetric carbon atoms.

Problem:

Problem 03 During 1 reaction, the leaving group leaves the molecule before the incoming group is attached to the molecule,

Problem:

Problem 04 In - emission from a nucleus the atomic number of the daughter element decreases by one.

Problem:

Problem 05 The rate of an exothermic reaction increases with increasing temperature.

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