# JEE Main

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 experienced teachers.

## Mathematics

States of Matter: Gases and Liquids

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Q 1. Density of a gas is found to be {tex}5.46 \mathrm { g } / \mathrm { dm } ^ { 3 } {/tex} at {tex} 27 ^ { \circ } \mathrm { C } {/tex} at {tex}\mathrm{2 \ bar}{/tex} pressure. What will be its density at STP?

A

6{tex} \mathrm { gm } / 1 {/tex}

B

8{tex} \mathrm { gm } / 1 {/tex}

3{tex} \mathrm { gm } / 1 {/tex}

D

1.5{tex} \mathrm { gm } /l {/tex}

##### Explanation

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Q 2. Calculate the temperature of 4.0 mole of a gas occupying 5{tex} \mathrm { dm } ^ { 3 } {/tex} at 3.32 bar. {tex} \left( \mathrm { R } = 0.83 \text { bar } \mathrm { dm } ^ { 3 } \mathrm { K } ^ { - 1 } \mathrm { mol } ^ { - 1 } \text { ) } \right. {/tex}

A

100{tex} \mathrm { K } {/tex}

50{tex} \mathrm { K } {/tex}

C

150{tex} \mathrm { K } {/tex}

D

200{tex} \mathrm { K } {/tex}

##### Explanation

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Q 3. Calculate the volume occupied by {tex} 8.8\mathrm { g } {/tex} of {tex} \mathrm { CO } _ { 2 } {/tex} at {tex} 31.1 ^ { \circ } \mathrm { C } {/tex} and 1 bar pressure. {tex}\mathrm R = 0.083 \mathrm { bar } \mathrm { LK } ^ { - 1 } \mathrm { mol } ^ { - 1 } {/tex} .

A

10.10{tex} \mathrm { ltr } {/tex}

B

8.05{tex} \mathrm { ltr } {/tex}

C

2.01{tex} \mathrm { ltr } {/tex}

5.05{tex} \mathrm { ltr } {/tex}

##### Explanation

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Q 4. {tex} 380\mathrm { mL } {/tex} of a gas at {tex} 27 ^ { \circ } \mathrm { C } , 800 \mathrm { mm } {/tex} of {tex}\mathrm{Hg}{/tex} weights {tex}0.455 \mathrm { g } . {/tex} The molecular weight of gas is

A

27

28

C

29

D

30

##### Explanation

The standard way to do this problem is to use the gas law equation: PV = nRT P = pressure = 800/760 = 1.053 atm V = volume = 0.380L n = number of moles R = gas law constant = 0.082057 T = temp in K = 27+273 = 300 Substitute: 1.053* 0.380 = n * 0.082057*300 n = ( 1.053*0.380) / ( 0.082057*300) n = 0.400/ 24.6171 n = 0.0162 mol 0.455g = 0.0162 mol 1mol = 0.455/ 0.0162 = 28.00g/mol

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Q 5. At what temperature will be the rate of effusion of {tex}\mathrm {N _ 2 } {/tex} be {tex}1.625{/tex} times the rate of effusion of {tex} \mathrm { SO } _ { 2 } {/tex} at {tex} 500 ^ { \circ } \mathrm { C } ? {/tex}

A

273{tex} \mathrm { K } {/tex}

830{tex} \mathrm { K } {/tex}

C

110{tex} \mathrm { K } {/tex}

D

173{tex} \mathrm { K } {/tex}

##### Explanation

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Q 6. What is the ratio of the rate of diffusion of {tex} \mathrm { O } _ { 2 } {/tex} and {tex} \mathrm { H } _ { 2 } {/tex} at same {tex} \mathrm P {/tex} and {tex} \mathrm T ? {/tex}

{tex} 1 : 4 {/tex}

B

{tex} 1 : 8 {/tex}

C

{tex} 1 : 16 {/tex}

D

{tex} 4 : 1 {/tex}

##### Explanation

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Q 7. Equal weights of methane and oxygen are mixed in an empty container at {tex} 25 ^ { \circ } \mathrm { C } {/tex} . What is the fraction of the total pressure exerted by oxygen?

{tex} \frac { 1 } { 3 } {/tex}

B

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

C

{tex} \frac { 2 } { 3 } {/tex}

D

{tex} \frac { 1 } { 3 } \times \frac { 273 } { 298 } {/tex}

##### Explanation

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Q 8. What will be the pressure of the gaseous mixture when {tex}0.5\mathrm{L}{/tex} of {tex} \mathrm { H } _ { 2 } {/tex} at {tex}\mathrm{0.8 \ bar}{/tex} and {tex}\mathrm{2.0L}{/tex} of dioxygen at {tex}\mathrm{0.7 \ bar}{/tex} are introduced in a {tex}\mathrm{1L}{/tex} vessel at {tex} 27 ^ { \circ } \mathrm { C } ? {/tex}

A

4 bar

1.8{tex} \mathrm { bar } {/tex}

C

0.9{tex} \mathrm { bar } {/tex}

D

3.6{tex} \mathrm { bar } {/tex}

##### Explanation

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Q 9. Calculate the total pressure in a mixture of {tex} 8\mathrm { g } {/tex} of dioxygen and {tex} 4\mathrm { g } {/tex} of dihydrogen confined in a vessel of {tex}1 \mathrm { dm } ^ { 3 } {/tex} at {tex} 27 ^ { \circ } \mathrm { C } .\mathrm R = 0.083 \, \mathrm { bar }\, \mathrm { dm } ^ { 3 } \mathrm { K } ^ { - 1 } \mathrm { mol } ^ { - 1 } . {/tex}

A

28.5 bar

56.025 bar

C

112.5 bar

D

14.25 bar

##### Explanation

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Q 10. A sample of gas at {tex} 35 ^ { \circ } \mathrm { C } {/tex} and {tex}\mathrm{1 \ atm}{/tex}pressure occupies a volume of {tex}\mathrm{3.75 \ ltr.}{/tex} At what temperature should the gas be kept if it is required to reduce the volume to {tex}\mathrm{3 \ ltr.}{/tex} at the same pressure?

{tex} - 26.6 ^ { \circ } \mathrm { C } {/tex}

B

{tex} 0 ^ { \circ } \mathrm { C } {/tex}

C

{tex} 3.98 ^ { \circ } \mathrm { C } {/tex}

D

{tex} 28 ^ { \circ } \mathrm { C } {/tex}

##### Explanation

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Q 11. The average speed of an ideal gas molecule at {tex} 27 ^ { \circ } \mathrm { C } {/tex} is {tex}0.3 \mathrm { m } \mathrm{sec^{-1}} {/tex} . The average speed at {tex} 927 ^ { \circ } \mathrm { C } {/tex} is

A

0.15{tex} \mathrm { m } \mathrm { sec } ^ { - 1 } {/tex}

0.6{tex} \mathrm { m } \mathrm { sec } ^ { - 1 } {/tex}

C

1.2{tex} \mathrm { m } \mathrm { sec } ^ { - 1 } {/tex}

D

0.6{tex} \mathrm { cm } \mathrm { sec } ^ { - 1 } {/tex}