1
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 9th January Morning Slot

0.5 moles of gas A and x moles of gas B exert a pressure of 200 Pa in a container of volume 10 m3 at 1000 K. Given R is the gas constant in JK$$-$$1mol$$-$$1, x is :
A
$${{2R} \over {4 + R}}$$
B
$${{2R} \over {4 - R}}$$
C
$${{4 + R} \over {2R}}$$
D
$${{4 - R} \over {2R}}$$

Explanation

We know,

PV = nRT

Given,

P = 200 Pa

V = 10 m3

T = 1000 K

n = 0.5 + x

$$ \therefore $$   200 $$ \times $$ 10 = (0.5 + x) R $$ \times $$ 1000

$$ \Rightarrow $$    0.5 + x = $${2 \over R}$$

$$ \Rightarrow $$    x = $${2 \over R} - {1 \over 2}$$

$$ \Rightarrow $$   x = $${{4 - R} \over {2R}}$$
2
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 12th January Morning Slot

The volume of gas A is twice than that of gas B. The compressibility factor of gas A is thrice than that of gas B at same temperature. The pressures of the gases for equal number of moles are -
A
2PA = 3PB
B
3PA = 2PB
C
PA = 3PB
D
PA = 2PB

Explanation

Z = PV/nRT

$$ \Rightarrow $$ P = $${{ZnRT} \over V}$$

at constant T and mol(n),

P $$ \propto $$ $${Z \over V}$$

$$ \Rightarrow $$ $${{{P_A}} \over {{P_B}}} = {{{Z_A}} \over {{Z_A}}} \times {{{V_B}} \over {{V_A}}}$$

= $$\left( {{3 \over 1}} \right) \times \left( {{1 \over 2}} \right)$$ = $${3 \over 2}$$

$$ \therefore $$ 2PA = 3PB
3
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 12th January Evening Slot

An open vessel at 27oC is heated until two fifth of the air (assumed as an ideal gas) it has escaped from the vessel assuming that the volume of the vessel remains constant, the temperature at which the vessel has been heated is -
A
750 K
B
500oC
C
750oC
D
500 K

Explanation

We know,

PV = nRT

As the vessel is open, so the pressure and volume is constant.

$$ \therefore $$   n1 R T1 = n2 R T2

$$ \Rightarrow $$   n1 T1 = n2 T1

$${2 \over 5}$$th of the air escape from the vessel. So the remaining air is $${3 \over 5}$$ of the total air.

$$ \therefore $$   n $$ \times $$ 300 = $${3 \over 5}$$n $$ \times $$ T2

$$ \Rightarrow $$   T2 = 500 K
4
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 9th April Morning Slot

Consider the van der Waals constants, a and b, for the following gases.

Gas Ar Ne Kr Xe
a/ (atm dm6 mol–2) 1.3 0.2 5.1 4.1
b/ (10–2 dm3 mol–1) 3.2 1.7 1.0 5.0

Which gas is expected to have the highest critical temperature?
A
Ne
B
Kr
C
Xe
D
Ar

Explanation

We know,

Critical temperature (Tc) = $${{8a} \over {27bR}}$$

$$ \therefore $$ Tc $$ \propto $$ $${a \over b}$$

So, species with greatest value of $${a \over b}$$ has greatest value of critical temperature.

Accordig to the given data Kr have highest $${a \over b}$$ ratio.

Questions Asked from Gaseous State

On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Name Indicates No of Questions
AIEEE 2002 (3)
keyboard_arrow_right
AIEEE 2003 (1)
keyboard_arrow_right
AIEEE 2004 (2)
keyboard_arrow_right
AIEEE 2005 (1)
keyboard_arrow_right
AIEEE 2010 (1)
keyboard_arrow_right
AIEEE 2011 (1)
keyboard_arrow_right
AIEEE 2012 (1)
keyboard_arrow_right
JEE Main 2013 (Offline) (1)
keyboard_arrow_right
JEE Main 2014 (Offline) (1)
keyboard_arrow_right
JEE Main 2016 (Offline) (1)
keyboard_arrow_right
JEE Main 2016 (Online) 9th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2016 (Online) 10th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2017 (Online) 8th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2017 (Online) 9th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2018 (Online) 16th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 9th January Morning Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 12th January Morning Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 12th January Evening Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 9th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 9th April Evening Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 10th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 10th April Evening Slot (1)
keyboard_arrow_right
JEE Main 2020 (Online) 2nd September Morning Slot (1)
keyboard_arrow_right
JEE Main 2020 (Online) 3rd September Evening Slot (1)
keyboard_arrow_right
JEE Main 2021 (Online) 26th August Evening Shift (1)
keyboard_arrow_right
JEE Main 2021 (Online) 27th August Morning Shift (1)
keyboard_arrow_right
JEE Main 2021 (Online) 31st August Morning Shift (1)
keyboard_arrow_right

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Graduate Aptitude Test in Engineering

GATE CSE GATE EE GATE ECE GATE ME GATE CE GATE PI GATE IN

Medical

NEET