JEE Chemistry Questions

Alkyl halides react with dialkyl copper reagents to give

Hydrocarbons Organic Halogens

Alkyl halides react with dialkyl copper reagents to give

  1. alkenes
  2. alkenyl halides
  3. alkanes
  4. alkyl copper halides

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During dehydration of alcohols to alkenes by heating with concentrated H2SO4

Hydrocarbons Organic Oxygen

During dehydration of alcohols to alkenes by heating with concentrated H2SO4 the initiation step is

  1. protonation of alcohol molecule
  2. formation of an ester
  3. formation of carbocation
  4. elimination of water

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Among the following compounds which can be dehydrated very easily

Organic Oxygen

Among the following compounds which can be dehydrated very easily?

  1. CH3CH2CH2CH2CH2OH
  2. CH3CH2CH2CHOHCH3
  3. CH3CH2CHCH3CH2CH2OH
  4. CH3CH2CH3COHCH2CH3

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Phenyl magnesium bromide reacts with methanol to give

Organic Oxygen

Phenyl magnesium bromide reacts with methanol to give

  1. a mixture of benzene and Mg(OMe)Br
  2. a mixture of anisole and Mg(OH)Br
  3. a mixture of phenol and Mg(Me)Br
  4. a mixture of toluene and Mg(OH)Br

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The IUPAC name of CH3COCH(CH3)2 is

Basic Organic Organic Oxygen

The IUPAC name of CH3COCH(CH3)2 is

  1. isopropylmethyl ketone
  2. 4-­methylisopropyl ketone
  3. 2-­methyl­-3-­butanone
  4. 3-­methyl-­2-­butanone

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Which one of the following undergoes reaction with 50% sodium hydroxide solution

Organic Oxygen

Which one of the following undergoes reaction with 50% sodium hydroxide solution to give the corresponding alcohol and acid?

  1. Butanol
  2. Phenol
  3. Benzaldehyde
  4. Benzoic acid

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Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon

Hydrocarbons Organic Oxygen

Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon?

  1. Acetic acid
  2. Butan­-2-­one
  3. Ethyl acetate
  4. Acetamide

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When primary amine reacts with chloroform in ethanoic KOH then the product is

Organic Nitrogen

When primary amine reacts with chloroform in ethanoic KOH then the product is

  1. an alcohol
  2. an isocyanide
  3. a cyanide
  4. an aldehyde

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The correct order of increasing basic nature for the bases NH3, CH3NH2 and (CH3)2NH is

Organic Nitrogen

The correct order of increasing basic nature for the bases NH3, CH3NH2 and (CH3)2NH is

  1. CH3NH2 < (CH3)2NH < NH3
  2. CH3NH2 < NH3 < (CH3)2NH
  3. (CH3)2NH < NH3 < CH3NH2
  4. NH3 < CH3NH2 < (CH3)2NH

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Which one of the following methods is neither meant for the synthesis nor for separation of amines

Organic Halogens Organic Nitrogen

Which one of the following methods is neither meant for the synthesis nor for separation of amines?

  1. Wurtz reaction
  2. Curtius reaction
  3. Hinsberg method
  4. Hofmann method

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Which one of the following is the strongest base in aqueous solution

Organic Nitrogen

Which one of the following is the strongest base in aqueous solution?

  1. Dimethylamine
  2. Aniline
  3. Trimethylamine
  4. Methylamine

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The species which can best serve as an initiator for the cationic polymerization is

Polymers

The species which can best serve as an initiator for the cationic polymerization is

  1. AlCl3
  2. BuLi
  3. LiAlH4
  4. HNO3

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RNA is different from DNA because RNA contains

Biomolecules

RNA is different from DNA because RNA contains

  1. ribose sugar and uracil
  2. deoxyribose sugar and uracil
  3. ribose sugar and thymine
  4. deoxyribose sugar and thymine

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The reason for double helical structure of DNA is operation of

Biomolecules

The reason for double helical structure of DNA is operation of

  1. electrostatic attractions
  2. dipole-­dipole interaction
  3. van der Waal's forces
  4. hydrogen bonding

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Complete hydrolysis of cellulose gives

Biomolecules

Complete hydrolysis of cellulose gives

  1. D-­fructose
  2. D-­glucose
  3. D­-ribose
  4. L-­glucose

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Which base is present in RNA but not in DNA

Biomolecules

Which base is present in RNA but not in DNA?

  1. Thymine
  2. Guanine
  3. Cytosine
  4. Uracil

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The term anomers of glucose refers to

Biomolecules

The term anomers of glucose refers to

  1. a mixture of (D)­glucose and (L)­glucose
  2. enantiomers of glucose
  3. isomers of glucose that differ in configuration at carbon one (C­1)
  4. isomers of glucose that differ in configurations at carbons one and four (C­1 and C­4)

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The secondary structure of a protein refers to

Biomolecules

The secondary structure of a protein refers to

  1. hydrophobic interactions
  2. fixed configuration of the polypeptide backbone
  3. sequence of α-­amino acids
  4. α ­helical backbone

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The two functional groups present in a typical carbohydrate are

Biomolecules

The two functional groups present in a typical carbohydrate are

  1. -CHO and -COOH
  2. >C=O and -OH
  3. -OH and -CHO
  4. -OH and -COOH

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Which one of the following groupings represents a collection of isoelectronic species

Atomic Structure

Which one of the following groupings represents a collection of isoelectronic species? (At. nos.: Cs-55, Br-­35)

  1. Ca2+, Cs+, Br
  2. Na+, Ca2+, Mg2+
  3. N3-, F, Na+
  4. Be, Al3+, Cl

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Which one of the following ions has the highest value of ionic radius

Periodic Properties

Which one of the following ions has the highest value of ionic radius?

  1. Li+
  2. F
  3. O2–
  4. B3+

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The increasing order of the first ionisation enthalpies of the elements B, P, S and F

Periodic Properties

The increasing order of the first ionisation enthalpies of the elements B, P, S and F (lowest first) is

  1. B < P < S < F
  2. F < S < P < B
  3. P < S < B < F
  4. B < S < P < F

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Aluminium is extracted by the electrolysis of

Isolation Metals

Aluminium is extracted by the electrolysis of

  1. bauxite
  2. molten cryolite
  3. alumina mixed with molten cryolite
  4. alumina

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Cyanide process is used for the extraction of

Isolation Metals

Cyanide process is used for the extraction of

  1. barium
  2. aluminium
  3. silver
  4. boron

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Which one of the following ores is best concentrated by froth ­flotation method

Isolation Metals

Which one of the following ores is best concentrated by froth ­flotation method?

  1. Cassiterite
  2. Malachite
  3. Magnetite
  4. Galena

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The number of hydrogen atom(s) attached to phosphorus atom in hypophosphorous acid is

Hydrogen

The number of hydrogen atom(s) attached to phosphorus atom in hypophosphorous acid is

  1. zero
  2. one
  3. two
  4. three

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Very pure hydrogen (99.9%) can be made by which of the following processes

Hydrogen

Very pure hydrogen (99.9%) can be made by which of the following processes?

  1. Reaction of salt like hydrides with water
  2. Reaction of methane with steam
  3. Mixing natural hydrocarbons of high molecular weight
  4. Electrolysis of water

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KO2 (potassium super oxide) is used in oxygen cylinders in space and submarines

s-Block

KO2 (potassium super oxide) is used in oxygen cylinders in space and submarines because it

  1. absorbs CO2
  2. eliminates moisture
  3. produces ozone
  4. absorbs CO2 and increases O2 content

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In curing cement plasters, water is sprinkled from time to time. This helps in

Hydrogen

In curing cement plasters, water is sprinkled from time to time. This helps in

  1. keeping it cool
  2. developing interlocking needle ­like crystals of hydrated silicates
  3. hydrating sand and gravel mixed with cement
  4. converting sand into silicic acid

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Several blocks of magnesium are fixed to the bottom of a ship to

s-Block

Several blocks of magnesium are fixed to the bottom of a ship to

  1. prevent puncturing by under ­sea rocks
  2. make the ship lighter
  3. prevent action of water and salt
  4. keep away the sharks

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The solubilities of carbonates decrease down the magnesium group due to a decrease in

s-Block

The solubilities of carbonates decrease down the magnesium group due to a decrease in

  1. hydration energies of cations
  2. lattice energies of solids
  3. inter-­ionic attraction
  4. entropy of solution formation

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The substance not likely to contain CaCO3 is

s-Block

The substance not likely to contain CaCO3 is

  1. a marble statue
  2. sea shells
  3. dolomite
  4. calcined gypsum

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Based on lattice energy and other consider cations which one of the following alkali metal chlorides

s-Block

Based on lattice energy and other consider cations which one of the following alkali metal chlorides is expected to have the highest melting point?

  1. LiCl
  2. NaCl
  3. KCl
  4. RbCl

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The ionic mobility of alkali metal ions in aqueous solution is maximum for

s-Block

The ionic mobility of alkali metal ions in aqueous solution is maximum for

  1. Li+
  2. Na+
  3. K+
  4. Rb+

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Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy

s-Block

Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy?

  1. BeSO4
  2. CaSO4
  3. SrSO4
  4. BaSO4

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Among Al2O3, SiO2, P2O3 and SO2 the correct order of acid strength is

p-Block

Among Al2O3, SiO2, P2O3 and SO2 the correct order of acid strength is

  1. Al2O3 < SiO2 < P2O3 < SO2
  2. Al2O3 < SiO2 < SO2 < P2O3
  3. SiO2 < SO2 < Al2O3 < P2O3
  4. SO2 < P2O3 < SiO2 < Al2O3

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A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed

Stoichiometry

A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed. The dried sample weighed 52 g. The formula of the hydrated salt is: (atomic mass, Ba = 137 amu, Cl = 35.5 amu)

  1. BaCl2.H2O
  2. BaCl2.2H2O
  3. BaCl2.3H2O
  4. BaCl2.4H2O

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Which of the following is not an assumption of the kinetic theory of gases

Gaseous State

Which of the following is not an assumption of the kinetic theory of gases?

  1. A gas consists of many identical particles which are in continual motion.
  2. Gas particles have negligible volume.
  3. At high pressure, gas particles are difficult to compress.
  4. Collisions of gas particles are perfectly elastic.

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If the principal quantum number n=6, the correct sequence of filling of electrons

Atomic Structure

If the principal quantum number n=6, the correct sequence of filling of electrons will be:

  1. ns→np→(n-1)d→(n-2)f
  2. ns→(n-2)f→(n-1)d→np
  3. ns→(n-1)d→(n-2)f→np
  4. ns→(n-2)f→np→(n-1)d

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The heat of atomization of methane and ethane are 360 kJ/mol and 620 kJ/mol, respectively

Chemical Thermodynamics

The heat of atomization of methane and ethane are 360 kJ/mol and 620 kJ/mol, respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number = 6.02×1023, h = 6.62×10-34 J s):

  1. 1.49×103 nm
  2. 2.48×103 nm
  3. 2.48×104 nm
  4. 1.49×104 nm

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A solution at 20°C is composed of 1.5 mol of benzene and 3.5 mol of toluene

Solutions

A solution at 20°C is composed of 1.5 mol of benzene and 3.5 mol of toluene. If the vapour pressure of pure benzene and pure toluene at this temperature are 74.7 torr and 22.3 torr, respectively, then the total vapour pressure of the solution and the benzene mole fraction in equilibrium with it will be, respectively:

  1. 35.0 torr and 0.480
  2. 38.0 torr and 0.589
  3. 30.5 torr and 0.389
  4. 35.8 torr and 0.280

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A stream of electrons from a heated filament was passed between two charged plates

Atomic Structure

A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If e and m are charge and mass of an electron, respectively, then the value of h/λ (where λ is wavelength associated with electron wave) is given by:

  1. 2meV
  2. √(meV)
  3. √(2meV)
  4. meV

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For a linear plot of log (x/m) versus log p in a Freundlich adsorption isotherm

Surface Chemistry

For a linear plot of log (x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct ? (k and n are constants)

  1. 1/n appears as the intercept.
  2. Only 1/n appears as the slope.
  3. log (1/n) appears as the intercept.
  4. Both k and 1/n appear in the slope term.

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The heats of combustion of carbon and carbon monoxide are –393.5 and –283.5

Chemical Thermodynamics

The heats of combustion of carbon and carbon monoxide are –393.5 and –283.5 kJ mol–1, respectively. The heat of formation (in kJ) of carbon monoxide per mole is:

  1. 676.5
  2. –676.5
  3. –110.5
  4. 110.5

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18 g glucose is added to 178.2 g water. The vapour pressure of water

Solutions

18 g glucose (C6H12O6) is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is:

  1. 76.0
  2. 752.4
  3. 759.0
  4. 7.6

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Which of the following is an anionic detergent

Everyday Life Chem

Which of the following is an anionic detergent?

  1. Sodium lauryl sulphate
  2. Cetyltrimethyl ammonium bromide
  3. Glyceryl oleate
  4. Sodium stearate

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The distillation technique most suited for separating glycerol from spent-lye

Everyday Life Chem

The distillation technique most suited for separating glycerol from spent-lye in the soap industry is:

  1. Fractional distillation
  2. Steam distillation
  3. Distillation under reduced pressure
  4. Simple distillation

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Decomposition of H2O2 follows a first order reaction. In fifty minutes the concentration

Chemical Kinetics

Decomposition of H2O2 follows a first order reaction. In fifty minutes the concentration of H2O2 decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of H2O2 reaches 0.05 M, the rate of formation of O2 will be:

  1. 6.93 × 10–4 mol min–1
  2. 2.66 L min–1 at STP
  3. 1.34 × 10–2 mol min–1
  4. 6.93 × 10–2 mol min–1

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The pair having the same magnetic moment is

df-Block

The pair having the same magnetic moment is:

[At. No.: Cr = 24, Mn = 25, Fe = 26, Co = 27]

  1. [Cr(H2O)6]2+ and [Fe(H2O)6]2+
  2. [Mn(H2O)6]2+ and [Cr(H2O)6]2+
  3. [CoCl4]2– and [Fe(H2O)6]2+
  4. [Cr(H2O)6]2+ and [CoCl4]2–

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