JEE Main > States of Matter: Gases and Liquids

Explore popular questions from States of Matter: Gases and Liquids for JEE Main. This collection covers States of Matter: Gases and Liquids previous year JEE Main questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

For an ideal gas, number of moles per litre in terms of its pressure {tex} \mathrm P {/tex}, gas constant {tex} \mathrm R {/tex} and temperature {tex}\mathrm T {/tex} is

A

{tex}\mathrm {P T / R} {/tex}

B

{tex} \mathrm {PRT} {/tex}

{tex} \mathrm {P / R T} {/tex}

D

{tex}\mathrm {R T / P} {/tex}.

Explanation

Q 2.    

Correct4

Incorrect-1

Value of gas constant {tex} R {/tex} is

A

0.082 litre atm

B

0.987 cal mol{tex} ^ { - 1 }{/tex}K{tex} ^ { - 1 }{/tex}

8.3 J mol{tex} ^ { - 1 }{/tex}K{tex} ^ { - 1 }{/tex}

D

83 erg mol{tex} ^ { - 1 }{/tex}K{tex} ^ { - 1 }{/tex}

Explanation

Q 3.    

Correct4

Incorrect-1

Kinetic theory of gases proves

A

only Boyle's law

B

only Charles' law

C

only Avogadro's law

All of these.

Explanation

Q 4.    

Correct4

Incorrect-1

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

A

in a wavy path

in a straight line path

C

with an accelerated velocity

D

in a circular path

Explanation

Q 5.    

Correct4

Incorrect-1

As the temperature is raised from {tex} 20 ^ { \circ } \mathrm { C } {/tex} to {tex} 40 ^ { \circ } \mathrm { C } {/tex} , the average kinetic energy of neon atoms changes by a factor of which of the following?

{tex} \frac { 313 } { 293 } {/tex}

B

{tex} \sqrt { ( 313 / 293 ) } {/tex}

C

{tex} \frac { 1 } { 2 } {/tex}

D

{tex}2{/tex}

Explanation

Q 6.    

Correct4

Incorrect-1

In van der Waals equation of state of the gas law, the constant {tex}'b'{/tex} is a measure of

volume occupied by the molecules

B

intermolecular attraction

C

intermolecular repulsions

D

intermolecular collisions per unit volume

Explanation

Q 7.    

Correct4

Incorrect-1

Which one of the following statements is NOT true about the effect of an increase in temperature on the distribution of molecular speeds in a gas?

A

The area under the distribution curve remains the same as under the lower temperature

B

The distribution becomes broader

C

The fraction of the molecules with the most probable speed increases

The most probable speed increases

Explanation





Q 8.    

Correct4

Incorrect-1

If {tex} 10 ^ { - 4 } \mathrm { dm } ^ { 3 } {/tex} of water is introduced into a {tex} 1.0 \mathrm { dm } ^ { 3 } {/tex} flask at {tex} 300 \mathrm { K } , {/tex} how many moles of water are in the vapour phase when equilibrium is established?
(Given : Vapour pressure of {tex} \mathrm { H } _ { 2 } \mathrm { O } {/tex} at {tex} 300 \mathrm { K } {/tex} is {tex}3170 \mathrm { Pa } {/tex} ; {tex} \left. R = 8.314 \mathrm { JK } ^ { - 1 } \mathrm { mol } ^ { - 1 } \right) {/tex}

A

{tex} 5.56 \times 10 ^ { - 3 } \mathrm { mol } {/tex}

B

{tex} 1.53 \times 10 ^ { - 2 } \mathrm { mol } {/tex}

C

{tex} 4.46 \times 10 ^ { - 2 } \mathrm { mol } {/tex}

{tex} 1.27 \times 10 ^ { - 3 } \mathrm { mol } {/tex}

Explanation

Q 9.    

Correct4

Incorrect-1

'a 'and 'b'are van der Waals' constants for gases. Chlorine is more easily liquefied than ethane because

A

a and b for Cl{tex}_ 2{/tex}> a and b for C{tex} _2{/tex}H{tex} _6{/tex}

B

a and b for Cl{tex}_ 2{/tex}< a and b for C{tex} _2{/tex}H{tex} _6{/tex}

a for Cl{tex}_ 2{/tex} < a for C{tex} _2{/tex}H{tex} _6{/tex} but b for Cl{tex}_ 2{/tex} > b for C{tex} _2{/tex}H{tex} _6{/tex}

D

a for Cl{tex}_ 2{/tex} > a for C{tex} _2{/tex}H{tex} _6{/tex} but b for Cl{tex}_ 2{/tex} < b for C{tex} _2{/tex}H{tex} _6{/tex}

Explanation

Q 10.    

Correct4

Incorrect-1

The compressibility factor for a real gas at high pressure is

A

{tex} 1 + \frac { R T } { p b } {/tex}

B

{tex}1{/tex}

{tex} 1 + \frac { p b } { R T } {/tex}

D

{tex} 1 - \frac { p b } { R T } {/tex}

Explanation



Q 11.    

Correct4

Incorrect-1

For gaseous state, if most probable speed is denoted by {tex} \mathrm { C } ^ { * } {/tex} , average speed by {tex} \overline { \mathrm { C } } {/tex} and mean square speed by {tex} \mathrm { C } , {/tex} then for a large number of molecules the ratios of these speeds are:

A

{tex} \mathrm { C } ^ { * } : \overline { \mathrm { C } } : \mathrm { C } = 1.225 : 1.128 : 1 {/tex}

{tex} \mathrm { C } ^ { * } : \overline { \mathrm { C } } : \mathrm { C } = 1.128 : 1.225 : 1 {/tex}

C

{tex} \mathrm { C } ^ { * } : \overline { \mathrm { C } } : \mathrm { C } = 1 : 1.128 : 1.225 {/tex}

D

{tex} \mathrm { C } ^ { * } : \overline { \mathrm { C } } : \mathrm { C } = 1 : 1.225 : 1.128 {/tex}

Explanation


Q 12.    

Correct4

Incorrect-1

If {tex} Z {/tex} is a compressibility factor, van der Waals equation at low pressure can be written as:

A

{tex} Z = 1 + \frac { R T } { P b } {/tex}

{tex} Z = 1 - \frac { a } { V R T } {/tex}

C

{tex} Z = 1 - \frac { P b } { R T } {/tex}

D

{tex} Z = 1 + \frac { P b } { R T } {/tex}

Explanation





Q 13.    

Correct4

Incorrect-1

The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is {tex} 1 : 4 . {/tex} The ratio of number of their molecule is:

A

{tex} 1 : 4 {/tex}

B

{tex} 7 : 32 {/tex}

{tex} 1 : 8 {/tex}

D

{tex} 3 : 16 {/tex}

Explanation

Q 14.    

Correct4

Incorrect-1

The intermolecular interaction that is dependent on the inverse cube of distance between the molecules is:

A

London force

hydrogen bond

C

ion- ion interaction

D

ion - dipole interaction

Explanation

Q 15.    

Correct4

Incorrect-1

Value of gas constant {tex} R {/tex} is

A

0.082 {tex} \mathrm { litre\ atm} {/tex}

B

0.987 cal {tex} \mathrm { mol } ^ { - 1 } \mathrm { K } ^ { - 1 } {/tex}

8.3 {tex} {}\mathrm { J } \mathrm { mol } ^ { - 1 } \mathrm { K } ^ { - 1 } {/tex}

D

83 erg {tex} \mathrm { mol } ^ { - 1 } \mathrm { K } ^ { - 1 } {/tex}

Explanation


Q 16.    

Correct4

Incorrect-1

Kinetic theory of gases proves

A

only Boyle's law

B

only Charles' law

C

only Avogadro's law

all of these.

Explanation





Q 17.    

Correct4

Incorrect-1

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

A

{tex} P T / R {/tex}

B

{tex} P R T {/tex}

{tex} P / R T {/tex}

D

{tex} R T / P {/tex}

Explanation


Q 18.    

Correct4

Incorrect-1

Na and Mg crystallize in {tex} b c c {/tex} and {tex} f c c {/tex} type crystals respectively, then the number of atoms of Na and Mg present in the unit cell of their respective crystal is

A

4 and 2

B

9 and 14

C

14 and 9

2 and 4

Explanation


Q 19.    

Correct4

Incorrect-1

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

2.57 x 10{tex}^{21}{/tex}

B

5.14 x 10{tex}^{21}{/tex}

C

1.28x 10{tex}^{21}{/tex}

D

1.71 x 10{tex}^{21}{/tex}

Explanation


Q 20.    

Correct4

Incorrect-1

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

A

in a circular path

B

in a wavy path

in a straight line path

D

with an accelerated velocity.

Explanation


Q 21.    

Correct4

Incorrect-1

A pressure cooker reduces cooking time for food because

A

heat is more evenly distributed in the cooking space

boiling point of water involved in cooking is increased

C

the higher pressure inside the cooker crushes the food material

D

cooking involves chemical changes helped by a rise in temperature.

Explanation


Q 22.    

Correct4

Incorrect-1

As the temperature is raised from {tex} 20 ^ { \circ } \mathrm { C } {/tex} to {tex} 40 ^ { \circ } \mathrm { C } , {/tex} the average kinetic energy of neon atoms changes by a factor of which of the following?

A

{tex} 1 / 2 {/tex}

B

{tex} \sqrt { 313 / 293 } {/tex}

{tex} 313 / 293 {/tex}

D

{tex} 2{/tex}

Explanation


Q 23.    

Correct4

Incorrect-1

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

A

intermolecular repulsions

B

intermolecular attraction

volume occupied by the molecules

D

intermolecular collisions per unit volume.

Explanation


Q 24.    

Correct4

Incorrect-1

What type of crystal defect is indicated in the diagram below?
{tex} \mathrm { Na } ^ { + } \mathrm { Cl } ^ { - } \mathrm { Na } ^ { + } \mathrm { Cl } ^ { - } \mathrm { Na } ^ { + } \mathrm { Cl } ^ { - } {/tex}
{tex} \mathrm { Cl } ^ { - } \square \mathrm { Cl } ^ { - } \mathrm { Na } ^ { + } \square \mathrm { Na } ^ { + } {/tex}
{tex} \mathrm { Na } ^ { + } \mathrm { Cl } ^ { - } \square \mathrm { Cl } ^ { - } \mathrm { Na } ^ { + } \mathrm { Cl } ^ { - } {/tex}
{tex} \mathrm { Cl } ^ { - } \mathrm { Na } ^ { + } \mathrm { Cl } ^ { - } \mathrm { Na } ^ { + } \square \mathrm { Na } ^ { + } {/tex}

A

Frenkel defect

Schottky defect

C

interstitial defect

D

Frenkel and Schottky defects.

Explanation


Q 25.    

Correct4

Incorrect-1

An ionic compound has a unit cell consisting of {tex} A {/tex} ions at the comers of a cube and {tex} B {/tex} ions on the centres of the faces of the cube. The empirical formula for this compound would be

A

{tex} A B {/tex}

B

{tex} A _ { 2 } B {/tex}

{tex} A B _ { 3 } {/tex}

D

{tex} A _ { 3 } B {/tex}

Explanation