JEE Questions

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

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

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

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

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

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

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

Organic Nitrogen

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

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

Polymers

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

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

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

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

Biomolecules

Complete hydrolysis of cellulose gives

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

Biomolecules

Which base is present in RNA but not in DNA?

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

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)

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

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

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

Periodic Properties

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

  1. Li+
  2. F
  3. O2–
  4. B3+

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

Isolation Metals

Aluminium is extracted by the electrolysis of

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

Isolation Metals

Cyanide process is used for the extraction of

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

Isolation Metals

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

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

Hydrogen

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

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

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

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

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

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

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

s-Block

The substance not likely to contain CaCO3 is

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

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

s-Block

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

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

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

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

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

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.

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

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

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

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

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.

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

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

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

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

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

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–

Measurement

The velocity of a particle depends upon t as V = A + Bt + ct2. If velocity is in m/s, the unit of A will be

  1. m/s
  2. m/s2
  3. m.s
  4. m2/s

Measurement

Which of the following pairs does not have the same dimensions?

  1. frequency and angular frequency
  2. angular velocity and velocity gradient
  3. velocity gradient and angular frequency
  4. angular frequency and potential energy gradient

Kinematics

A particle has an initial velocity of 3i + 4j and an acceleration of 0.4i + 0.3j. Its speed after 10s is

  1. 7(√2) units
  2. 10 units
  3. 7 units
  4. 8.5 units

Laws of Motion

A block of mass m is placed on a surface with a vertical cross section given by y = x3/6. If the coefficient of friction is 0.5, the maximum height above the ground at which the block can be placed without slipping is:

  1. 1/6 m
  2. 1/3 m
  3. 1/2 m
  4. 2/3 m