For one mole of a van der Waals' gas, the compressibility factor Z = p V R T at a fixed volume will certainly decrease, if [Given : " a " and " b " are standard parameters for van der Waals' gas]

" b " decreases and " a " increases at constant temperature

" b " increases and " a " decreases at constant temperature

temperature increases at constant a n and " b " values

" b " increases at constant " a " and temperature

Van der Waal's equation for a gas is stated as, P = nRT V - nb - a n V 2 . This equation reduces to the perfect gas equation, P = nRT V When,

temperature is sufficiently high and pressure is low.

both temperature and pressure are very low.

both temperature and pressure are very high.

temperature is sufficiently low and pressure is high.

EASY

Earn 100

Deviation from the ideal gas behavior of a gas can be expressed as

60% studentsanswered this correctly

Important Questions on States of Matter

MEDIUM

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

When does a gas deviate the most from its ideal behavior?

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

A certain gas obeys

P (V_{m} - b) = RT

. The value of

{(\frac{\partial Z}{\partial P})}_{T}

\frac{xb}{RT}

. The value of

x

is (Integer answer) (

Z

: compressibility factor)

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

A gas such as carbon monoxide would be most likely to obey the ideal gas law at:

HARD

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

Which one of the following plots is correct for the behaviour of ideal and real gases?

HARD

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

For one mole of a van der Waals' gas, the compressibility factor

Z = (\frac{p V}{R T})

at a fixed volume will certainly decrease, if
[Given : " a " and " b " are standard parameters for van der Waals' gas]

MEDIUM

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The variation of the compressibility factor $(Z)$ with pressure $(P in bar)$ for some gases, are shown in the figure below. Identify the gases $(A), (B)$ and $(C)$ .

Question Image

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The compressibility factor

(Z)

of a gas is

< 1

at STP. Therefore

MEDIUM

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The van der Waals constant

' a'

is the measure of intermolecular force of attraction in a gas. The correct decreasing order of

' a'

for the given set of molecules is

MEDIUM

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

Which of the following gases has high Boyle's temperature?

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

For an ideal gas, the compressibility factor is

MEDIUM

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The pressure

(p)

and volume

(V)

isotherm of a van der Waals' gas, at the temperature at which it undergoes gas to liquid transition, is correctly represented by

HARD

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

If Z is the compressibility factor, then Van der Waal's equation at low pressure can be written as:

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The number density of molecules of a gas depends on their distance r from the origin as,

n (r) = n_{0} e^{- α r^{4}} .

Then the numer of molecules is proportional to:

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

Among the following, the incorrect statement is:

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The maximum deviation from ideal gas behaviour among the following is expected from

HARD

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

Van der Waal's equation for a gas is stated as,

P = \frac{nRT}{V - nb} - a {(\frac{n}{V})}^{2}

.

This equation reduces to the perfect gas equation,

P = \frac{nRT}{V}

When,

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

For a van der Waals' gas, the term $(\frac{ab}{V^{2}})$ represents some

HARD

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

The isotherms of a gas are shown below :

Question Image

Among the following,

(i) At $T_{1}$ , the gas cannot be liquefied

(ii) At point $B$ , liquid starts to appear at $T_{2}$

(ii) $T_{C}$ is the highest temperature at which the gas can be liquefied

(iv) At point $A$ , a small increase in pressure condenses the whole system to a liquid

The correct statements are :

MEDIUM

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

A gas at

350 K

and

15

bar has a molar volume

20

per cent smaller than that for an ideal gas under the same conditions. The correct option about the gas, and its compressibility factor

(Z)

EASY

Chemistry>Physical Chemistry>States of Matter>Behaviour of Real Gases

In the following compressibility factor (Z) vs pressure graph at 300 K, the compressibility of

C H_{4}

at pressure < 200 bar deviates from ideal behavior because

Question Image

Deviation from the ideal gas behavior of a gas can be expressed as

Important Questions on States of Matter

Learn and Prepare for any exam you want !