H 2 O is subjected to different phase change at different temperatures and pressures as shown in List-I. The entropy change of system, surrounding and total in shown in List-II. List - I List - II (

Question

H 2 O is subjected to different phase change at different temperatures and pressures as shown in List-I. The entropy change of system, surrounding and total in shown in List-II. List - I List - II (P) H 2 O ( ℓ , 10 0 ∘ C , 2 atm ) ⟶ H 2 O ( g , 10 0 ∘ C , 2 atm ) (1) Δ S sys < 0 , Δ S sur > 0 , Δ S total > 0 (Q) H 2 O ( g , 10 0 ∘ C , 0.5 atm ) → H 2 O ( ℓ , 10 0 ∘ C , 0.5 atm ) (2) Δ S sys > 0 , Δ S sur < 0 , Δ S total > 0 (R) H 2 O ( ℓ , − 1 0 ∘ C , 1 atm ) → H 2 O ( s , − 1 0 ∘ C , 1 atm ) (3) Δ S sys > 0 , Δ S sur > 0 , Δ S total > 0 (S) H 2 O ( s , 0 ∘ C , 2 atm ) → H 2 O ( ℓ , 0 ∘ C , 2 atm ) (4) Δ S sys > 0 , Δ S sur < 0 , Δ S total < 0 (5) Δ S sys < 0 , Δ S sur > 0 , Δ S total < 0 Match List-I with List-II and choose the correct option :

TestHub · Accepted Answer

Liquid → Gas or Solid → Liquid ⇒ Δ S > 0 Gas → Liquid or Liquid → Solid ⇒ Δ S < 0 At 100 ℃, boiling occurs at 1 atm, so at 2 atm vaporization is non-spontaneous ⇒ Δ G > 0 . Thus P → (4). Condensation at 0.5 atm and 25℃ is spontaneous ⇒ Δ G < 0 . Thus Q → (5). Freezing at − 5℃ is spontaneous ⇒ R → (1). Melting at − 5℃ and 2 atm is non-spontaneous ⇒ S → (2). Hence, P→4, Q→5, R→1, S→2 ⇒ Option (A).

List - I	List - II
(P) $H_{2} O_{(ℓ, 10 0^{\circ} C, 2 atm)} ⟶ H_{2} O_{(g, 10 0^{\circ} C, 2 atm)}$	(1) $Δ S_{sys} < 0, Δ S_{sur} > 0, Δ S_{total} > 0$
(Q) $H_{2} O_{(g, 10 0^{\circ} C, 0.5 atm)} \to H_{2} O_{(ℓ, 10 0^{\circ} C, 0.5 atm)}$	(2) $Δ S_{sys} > 0, Δ S_{sur} < 0, Δ S_{total} > 0$
(R) $H_{2} O_{(ℓ, - 1 0^{\circ} C, 1 atm)} \to H_{2} O_{(s, - 1 0^{\circ} C, 1 atm)}$	(3) $Δ S_{sys} > 0, Δ S_{sur} > 0, Δ S_{total} > 0$
(S) $H_{2} O_{(s, 0^{\circ} C, 2 atm)} \to H_{2} O_{(ℓ, 0^{\circ} C, 2 atm)}$	(4) $Δ S_{sys} > 0, Δ S_{sur} < 0, Δ S_{total} < 0$
	(5) $Δ S_{sys} < 0, Δ S_{sur} > 0, Δ S_{total} < 0$

Chemistry - Thermodynamics - II Question with Solution | TestHub

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