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

HARD

Earn 100

The criterion of spontaneity in terms of Gibbs energy is the same as that laid down by second law of thermodynamics. How?

Important Questions on Thermodynamics

EASY

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second Law of Thermodynamics

State the second law of thermodynamics.

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second 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-

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second Law of Thermodynamics

The true statement amongst the following is:

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second 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>Thermodynamics>Entropy and Second 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>Thermodynamics>Entropy and Second Law of Thermodynamics

Calculate the entropy change in melting

1

mole of ice at

273 K ({ΔH}_{f}^{°} = 6.025 kJ {mol}^{- 1})

EASY

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second Law of Thermodynamics

In which case change in entropy is negative?

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second 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

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second Law of Thermodynamics

For which of the following processes,

∆ S

is negative?

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second Law of Thermodynamics

The entropy change in the isothermal reversible expansion of 2 moles of an ideal gas from 10 to 100 at 300 K is

EASY

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second Law of Thermodynamics

When the same quantity of heat is absorbed by a system at two different temperatures

T_{1}

and

T_{2}

, such that

T_{1} > T_{2}

, change in entropies are

Δ S_{1}

and

Δ S_{2}

respectively. Then:

HARD

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second 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

)

MEDIUM

Chemistry>Physical Chemistry>Thermodynamics>Entropy and Second 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 $298 K$ ?