JEE Chemistry Questions

Which aqueous solutions will exhibit highest boiling point

• Solutions

Which one of the following aqueous solutions will exhibit highest boiling point?

1. 0.01 M KNO₃
2. 0.015 M urea
3. 0.01 M Na₂SO₄
4. 0.015 M glucose

Equimolal solutions in the same solvent have

• Solutions

Equimolal solutions in the same solvent have

1. Same boiling and same freezing points.
2. Different boiling and different freezing points.
3. Same freezing point but different boiling point.
4. Same boiling point but different freezing point.

Two solutions of a substance (non electrolyte) are mixed in the following manner

• Solutions

Two solutions of a substance (non electrolyte) are mixed in the following manner:

480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution

What is the molarity of the final mixture?

1. 2.70 M
2. 1.50 M
3. 1.344 M
4. 1.20 M

Benzene and toluene form nearly ideal solutions

• Solutions

Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20°C for a solution containing 78 g of benzene and 46 g of toluene in torr is

1. 25
2. 37.5
3. 50
4. 53.5

In a 0.2 molal aqueous solution of a weak acid HX

• Solutions

In a 0.2 molal aqueous solution of a weak acid HX, the degree of ionization is 0.3. Taking K_f for water as 1.85, the freezing point of the solution will be nearest to

1. – 0.480 °C
2. – 0.360 °C
3. – 0.260 °C
4. + 0.480 °C

How many unit cells are present in a cube-shaped ideal crystal

• States Matter

How many unit cells are present in a cube-shaped ideal crystal of NaCl of mass 1.00 g? [Atomic masses: Na = 23, Cl = 35.5]

1. 2.57 × 10²¹
2. 1.28 × 10²¹
3. 1.71 × 10²¹
4. 5.14 × 10²¹

In a compound, atoms of element Y form ccp lattice

• States Matter

In a compound, atoms of element Y form ccp lattice and those of element X occupy 2/3^rd of tetrahedral voids. The formula of the compound will be

1. X₂Y
2. X₃Y₄
3. X₄Y₃
4. X₂Y₃

If Z is a compressibility factor, van der Waals equation at low pressure

• Gaseous State

If Z is a compressibility factor, van der Waals equation at low pressure can be written as

1. Z = 1+Pb/RT
2. Z = 1-a/(VRT)
3. Z = 1+RT/Pb
4. Z = 1-Pb/RT

Equal masses of methane and oxygen are mixed in an empty container

• Gaseous State

Equal masses of methane and oxygen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by oxygen is

1. 1/2
2. 1/3
3. 2/3
4. (1/3) * (273/298)

Lithium forms body centred cubic structure

• States Matter

Lithium forms body centred cubic structure. The length of the side of its unit cell is 351 pm. Atomic radius of the lithium will be

1. 75 pm
2. 152 pm
3. 240 pm
4. 300 pm

According to the kinetic theory of gases, in an ideal gas

• Gaseous State

According to the kinetic theory of gases, in an ideal gas, between two successive collisions a gas molecule travels

1. in a straight line path
2. in a wavy path
3. in a circular path
4. with an accelerated velocity

In van der Waals equation of state of the gas law, the constant b

• Gaseous State

In van der Waals equation of state of the gas law, the constant b is a measure of

1. volume occupied by the molecules
2. intermolecular attraction
3. intermolecular repulsions
4. intermolecular collisions per unit volume

The correct order of bond angles (smallest first)

• Chemical Bonding

The correct order of bond angles (smallest first) in H₂S, NH₃, BF₃ and SiH₄ is

1. H₂S < NH₃ < SiH₄ < BF₃
2. NH₃ < H₂S < SiH₄ < BF₃
3. H₂S < SiH₄ < NH₃ < BF₃
4. H₂S < NH₃ < BF₃ < SiH₄

The bond order in NO is 2.5 while that in NO+ is 3

• Chemical Bonding

The bond order in NO is 2.5 while that in NO⁺ is 3. Which of the following statements is true for these two species?

1. Bond length is unpredictable
2. Bond length in NO⁺ is equal to that in NO
3. Bond length in NO⁺ is greater than in NO
4. Bond length in NO is greater than in NO⁺

The molecule having smallest bond angle is

• Chemical Bonding

The molecule having smallest bond angle is

1. AsCl₃
2. PCl₃
3. SbCl₃
4. NCl₃

A square planar complex is formed by hybridisation

• Chemical Bonding

A square planar complex is formed by hybridisation of which atomic orbitals?

1. s, p_x, p_y, p_z
2. s, p_x, p_y, p_z, d
3. d, s, p_x, p_y
4. s, p_x, p_y, p_z, d, d

In Bohr series of lines of hydrogen spectrum

• Atomic Structure

In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following interorbit jumps of the electron for Bohr orbits in an atom of hydrogen?

1. 2 → 5
2. 4 → 1
3. 5 → 2
4. 3 → 2

Which sets of quantum numbers is correct for an electron in 4f orbital

• Atomic Structure

Which of the following sets of quantum numbers is correct for an electron in 4f orbital?

1. n = 4, l = 4, m = –4, s =-1/2
2. n = 4, l = 3, m = +4, s =+1/2
3. n = 3, l = 2, m = –2, s =+1/2
4. n = 4, l = 3, m = +1, s =+1/2

Which statements in relation to the hydrogen atom is correct

• Atomic Structure

Which of the following statements in relation to the hydrogen atom is correct?

1. 3s orbital is lower in energy than 3p orbital
2. 3s, 3p and 3d orbitals all have the same energy
3. 3s and 3p orbitals are of lower energy than 3d orbital
4. 3p orbital is lower in energy than 3d orbital

The number of neutrons in the element L is

• Atomic Structure

Consider the following nuclear reactions:

²³⁸₉₂M → ^X_YN + 2⁴₂He  ;  ^X_YN → ^A_BL + 2β⁺

The number of neutrons in the element L is

1. 146
2. 144
3. 142
4. 140

How many moles of magnesium phosphate

• Stoichiometry

How many moles of magnesium phosphate, Mg₃(PO₄)₂ will contain 0.25 mole of oxygen atoms?

1. 2.5 x 10^-2
2. 0.02
3. 1.25 x 10^-2
4. 3.125 x 10^-2

If we consider that 1/6, in place of 1/12, mass of carbon atom

• Stoichiometry

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

1. decrease twice
2. remain unchanged
3. increase two fold
4. be a function of the molecular mass of the substance

With increase of temperature, which of these changes

• Stoichiometry

With increase of temperature, which of these changes?

1. molality
2. molarity
3. mole fraction
4. weight fraction of solute

What volume of hydrogen gas, at 273 K and 1 atm

• Stoichiometry

What volume of hydrogen gas, at 273 K and 1 atm. pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?

1. 89.6 L
2. 67.2 L
3. 44.8 L
4. 22.4 L

Number of atoms in 558.5 gram Fe

• Stoichiometry

Number of atoms in 558.5 gram Fe (atomic weight of Fe = 55.85 g mol^–1) is

1. twice that in 60 g carbon
2. 558.5 × 6.023 × 10²³
3. half that in 8 g He
4. 6.023 × 10²²

In the reaction, 2Al (s) + 6HCl (aq)

• Stoichiometry

In the reaction,

2Al (s) + 6HCl (aq) → 2Al³⁺ (aq) + 6Cl^– (aq) + 3H₂ (g)

1. 6 L HCl (aq) is consumed for every 3 L H₂(g) produced
2. 11.2 L H₂(g) at STP is produced for every mole HCl (aq) consumed
3. 33.6 L H₂(g) is produced regardless of temperature and pressure for every mole Al that reacts
4. 67.2 L H₂(g) at STP is produced for every mole Al that reacts

The molecular formula of a commercial resin used for exchanging ions

• Stoichiometry

The molecular formula of a commercial resin used for exchanging ions in water softening is C₈H₇SO₃Na (Mol. Wt. 206). What would be the maximum uptake of Ca²⁺ ions by the resin when expressed in mole per gram resin?

1. 2/309
2. 1/103
3. 1/206
4. 1/412

Which of the following is the energy of a possible excited state of hydrogen

• Atomic Structure

Which of the following is the energy of a possible excited state of hydrogen?

1. - 6.8 eV
2. - 3.4 eV
3. + 6.8 eV
4. + 13.6 eV

The ionic radii (in Å) of N3–, O2– and F– are respectively

• Periodic Properties

The ionic radii (in Å) of N^3–, O^2– and F^– are respectively

1. 1.36, 1.71 and 1.40
2. 1.71, 1.40 and 1.36
3. 1.71, 1.36 and 1.40
4. 1.36, 1.40 and 1.71

The color of KMnO4 is due to

• df-Block

The color of KMnO₄ is due to

1. d – d transition
2. L → M charge transfer transition
3. σ – σ* transition
4. M → L charge transfer transition

Which of the following compounds is not an antacid

• Everyday Life Chem

Which of the following compounds is not an antacid?

1. Cimetidine
2. Phenelzine 
3. Ranitidine
4. Aluminium hydroxide

In the context of the Hall-Heroult process for the extraction of Al

• Isolation Metals

In the context of the Hall-Heroult process for the extraction of Al, which of the following statements is false?

1. Al₂O₃ is mixed with CaF₂ which lowers the melting point of the mixture and brings conductivity
2. Al³⁺ is reduced at the cathode to form Al
3. Na₃AlF₆ serves as the electrolyte
4. CO and CO₂ are produced in this process

Which polymer is used in the manufacture of paints and lacquers

• Polymers

Which polymer is used in the manufacture of paints and lacquers?

1. Glyptal
2. Polypropene
3. Poly vinyl chloride
4. Bakelite

In a compound C, H and N atoms are present in 9:1:3.5 by weight

• Stoichiometry

In a compound C, H and N atoms are present in 9:1:3.5 by weight. Molecular weight of compound is 108. Molecular formula of compound is

1. C₉H₁₂N₃
2. C₃H₄N
3. C₆H₈N₂
4. C₂H₆N₂

Number of atoms in 558.5 gram Fe is

• Atomic Structure

Number of atoms in 558.5 gram Fe (atomic weight of Fe = 55.85 g mol^–1) is

1. twice that in 60 g carbon
2. half that in 8 g He
3. 6.023 × 10²²
4. 558.5 × 6.023 × 10²³

The de Broglie wavelength of a tennis ball of mass 60 g

• Atomic Structure

The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 metres per second is approximately (Planck's constant, h = 6.63 × 10^–34 Js)

1. 10^–16 metres
2. 10^–31 metres
3. 10^–33 metres
4. 10^–25 metres

Which one of the following compounds has the smallest bond angle

• Chemical Bonding

Which one of the following compounds has the smallest bond angle in its molecule?

1. NH₃
2. SH₂
3. SO₂
4. OH₂

For an ideal gas, number of moles per litre in terms of its pressure

• States Matter
• Gaseous State

For an ideal gas, number of moles per litre in terms of its pressure P, gas constant R and temperature T is

1. P/RT
2. PT/R
3. RT/P
4. PRT

The enthalpy change for a reaction does not depend upon the

• Chemical Thermodynamics

The enthalpy change for a reaction does not depend upon the

1. use of different reactants for the same product.
2. nature of intermediate reaction steps.
3. physical states of reactants and products.
4. difference in initial or final temperatures of involved substances.

Butene-­1 may be converted to butane by reaction with

• Hydrocarbons

Butene-­1 may be converted to butane by reaction with

1. Zn-Hg
2. Sn-HCl
3. Zn-­HCl
4. Pd/H₂

On mixing a certain alkane with chlorine and irradiating it with ultraviolet light

• Hydrocarbons
• Organic Halogens

On mixing a certain alkane with chlorine and irradiating it with ultraviolet light, it forms only one monochloroalkane. This alkane could be

1. neopentane
2. pentane
3. propane
4. isopentane

2-­Methylbutane on reacting with bromine in the presence of sunlight gives mainly

• Organic Halogens

2-­Methylbutane on reacting with bromine in the presence of sunlight gives mainly

1. 2-­bromo­-2-­methylbutane
2. 1-­bromo-­3-­methylbutane
3. 2-­bromo-­3-­methylbutane
4. 1-­bromo-­2-­methylbutane

Presence of a nitro group in a benzene ring

• Organic Nitrogen

Presence of a nitro group in a benzene ring

1. deactivates the ring towards nucleophilic substitution
2. activates the ring towards electrophilic substitution
3. renders the ring basic
4. deactivates the ring towards electrophilic substitution

The reaction of toluene with Cl2 in presence of FeCl3 gives predominantly

• Hydrocarbons
• Organic Halogens

The reaction of toluene with Cl₂ in presence of FeCl₃ gives predominantly

1. benzoyl chloride
2. m-­chlorobenzene
3. benzyl chloride
4. o­- and p­-chlorotoluene

Which of the following reactions will yield 2, 2-­dibromopropane

• Hydrocarbons
• Organic Halogens

Which of the following reactions will yield 2, 2-­dibromopropane?

1. C₂H₂ + 2HBr →
2. CH₃CHCH₂ + 2HBr →
3. CH₃CHCHBr + HBr →
4. CH₃CCH + 2HBr →

The hydrocarbon which can react with sodium in liquid ammonia is

• Hydrocarbons

The hydrocarbon which can react with sodium in liquid ammonia is

1. CH₃CHCHCH₃
2. CH₃CH₂C≡CCH₂CH₃
3. CH₃CH₂CH₂C≡CCH₂CH₂CH₃
4. CH₃CH₂C≡CH

The alkene that exhibits geometrical isomerism is

• Hydrocarbons
• Basic Organic

The alkene that exhibits geometrical isomerism is

1. 2-methyl propene
2. 2 methyl 2 butene
3. 2-Butene
4. propene

The IUPAC name of neopentane is

• Basic Organic

The IUPAC name of neopentane is

1. 2 – methylpropane
2. 2, 2 – dimethylpropane
3. 2 – methylbutane
4. 2, 2 – dimethylbutane

One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde

• Hydrocarbons
• Organic Oxygen

One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is

1. 1-butene
2. 2-butene
3. propene
4. ethene

Ozonolysis of an organic compound gives formaldehyde as one of the products

• Hydrocarbons
• Organic Oxygen

Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of

1. an acetylenic triple bond
2. a vinyl group
3. two ethylenic double bonds
4. an isopropyl group