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.

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Under which of the following conditions does a gas deviate the most from ideal behaviour?

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Important Questions on States of Matter

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

Gases deviate from ideal behaviour at high pressures because the gas molecules

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)

HARD

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

One mole of a monoatomic real gas satisfied the equation

p (V - b) = R T

where b is a constant. The relationship of interatomic potential V(r) and interatomic distance r for the gas is given by

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

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,

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:

MEDIUM

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

At low pressure, the Van der Waals equation is reduced to:

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?

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

EASY

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

At very high pressures, the compressibility factor of one mole of a gas is given by:

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

At a given temperature

T,

gases

N e, A r, X e

and

K r

are found to deviate from ideal gas behaviour. Their equation of state is given as

p = \frac{R T}{V - b}

T .

Here,

b

is the van der Waals constant. Which gas will exhibit steepest increase in the plot of

Z

(compression factor) vs

p ?

EASY

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

For an ideal gas, the compressibility factor is

HARD

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

In thermodynamics, the $P - V$ work done is given by $w = - \int {dVP}_{ext}$ . For a system undergoing a particular process, the work done is,

$w = - \int dV (\frac{RT}{V - b} - \frac{a}{V^{2}})$ . This equation is applicable to a

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

EASY

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

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

MEDIUM

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

The internal energy per mole of an ideal gas is denoted by

E_{ideal}

. The same for a real gas obeying van der Waals equation is

E_{real}

. Assuming the average kinetic energy of the molecules of the two gases at the same temperature to be equal, the correct statement for the gas at low pressure is

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

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

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

Under which of the following conditions does a gas deviate the most from ideal behaviour?

Important Questions on States of Matter

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