For the process H 2 O l → H 2 O g at T = 100 o C and 1 atmosphere pressure, the correct choice is-

∆ S s y s t e m > 0 a n d ∆ S s u r r o u n d i n g < 0

∆ S s y s t e m > 0 a n d ∆ S s u r r o u n d i n g > 0

∆ S s y s t e m < 0 a n d ∆ S s u r r o u n d i n g > 0

∆ S s y s t e m < 0 ∆ S s u r r o u n d i n g < 0

EASY

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Identify the correct statement regarding entropy.

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Important Questions on Chemical Thermodynamics

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

Two ideal Carnot engines operate in a cascade (all heat given up by one engine is used by the other engine to produce work) between temperatures,

T_{1}

and

T_{2}

. The temperature of the hot reservoir of the first engine is

T_{1}

and the temperature of the cold reservoir of the second engine is

T_{2}

T

is the temperature of the sink of the first engine which is also the source for the second engine. How is

T

related to

T_{1}

and

T_{2}

, if both the engines perform an equal amount of work?

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature on its equilibrium constant

K

in terms of change in entropy is described by:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

The true statement amongst the following is:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

For the following reaction

${Fe}_{2} O_{3 (s)} + 3 {CO}_{(g)} ⟶ 2 {Fe}_{(s)} + 3 {CO}_{2 (g)} ΔH ° = - 29.8 kJ$ and $ΔS ° = 15 {JK}^{- 1}$ . What is the value of ${ΔS}_{(total)}$ at $298 K$ ?

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

The process with negative entropy change is:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

Which of the following show an increase in entropy?

I. Boiling of water

II. Melting of ice

III. Freezing of water

IV. Formation of hydrogen gas from water

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

In which case change in entropy is negative?

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

During which of the following processes, does entropy decrease ?

(A) Freezing of water to ice at $0 ° C$
(B) Freezing of water to ice at $- 10 ° C$
(C) $N_{2} (g) + 3 H_{2} (g) \to 2 {NH}_{3} (g)$
(D) Adsorption of $CO (g)$ and lead surface
(E) Dissolution of $NaCl$ in water

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

For a sample of perfect gas, when its pressure is changed isothermally from

p_{i}

p_{f}

, the entropy change is given by

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

For which of the following processes,

∆ S

is negative?

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

State the second law of thermodynamics.

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

Consider the following liquid - vapour equilibrium.

L i q u i d ⇌ V a p o u r

Which of the following relations is correct?

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

A container is divided into two compartments by a removable partition as shown below:

Question Image

In the first compartment, $n_{1}$ moles of ideal gas He is present in a volume $V_{1} .$ In the second compartment, $n_{2}$ moles of ideal gas $Ne$ is present in a volume $V_{2} .$ The temperature and pressure in both the compartments are $T$ and $P,$ respectively. Assuming $R$ is the gas constant, the total change in entropy upon removing the partition when the gases mix irreversibly is:

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

For the reaction,

2 Cl (g) \to {Cl}_{2} (g)

, the correct option is

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

Standard molar entropy is

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

What will be the entropy change of the system when expansion of

1

mole of a gas takes place from

3 L

6 L

under isothermal conditions? Consider

R = 2 cal K^{- 1} {mole}^{- 1}

and

\log 2 = 0.301 .

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

The entropy of a perfectly crystalline solid at absolute zero temperature is:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

For the process

H_{2} O (l) \to H_{2} O (g)

T = 100^{o} C

and

1

atmosphere pressure, the correct choice is-

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

The entropy change associated with the conversion of

1 k g

of ice at

273 K

to water vapours at

383 K

is:

(Specific heat of water liquid and water vapour are

4.2 k J K^{-}

and

2.0 k J K^{- 1} k g^{- 1}

; heat of liquid fusion and vaporization of water are

334 k J k g^{- 1}

and

2491 k J k g^{- 1}

, respectively). (

l o g

273 = 2.436, \log 373 = 2.572, \log 383 = 2.583

)

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Third Law of Thermodynamics

One mole of an ideal gas at

300 K

in thermal contact with its surroundings expands isothermally from

1.0 L

2.0 L

against a constant pressure of

3.0 atm

. In this process, the change in entropy of the surroundings

(∆ S_{s u r r})

J K^{- 1}

is:

(1 L atm = 101.3 J)

Identify the correct statement regarding entropy.

Important Questions on Chemical Thermodynamics

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