Chemistry - Thermodynamics - I Question with Solution | TestHub

ChemistryThermodynamics - IFirst law of ThermodynamicsEasy2 minPYQ_2020
ChemistryEasysingle choice

Calculate Δ f G ∘ for (NH4Cl, s) at 310 K.

Given : Δ f H ∘ NH 4 Cl, s = - 314.5 kJ/mol ; Δ r C p = 0

S N 2 g ∘ = 192 JK -1 mol -1 ;   S H 2 g ∘ = 130.5 JK -1 mol -1 ;

S Cl 2 g ∘ = 233 JK -1 mol -1 ;   S NH 4 Cl s ∘ = 99.5 JK -1 mol -1

All given data at 300 K.

Options:

Answer:
A
Solution:

∆fS0NH4Cl,s at 300 K

= S N H 4 Cl(S) 0 −[ 1 2 S N 2 0 +2 S H 2 0 + 1 2 S C l 2 0 ]

= -374 JK-1mol-1  

∴ ∆fCp=0

∴  ∆fS3100=∆rS3000

= -374 JK-1mol-1

∆fH3100=∆fH3000=-314.5

∆fG3100=∆fH0-310∆fS0

= -314.5-310-3741000

-198.56 kJ/mol

Stream:NTA_ABHYAS_NEETSubject:ChemistryTopic:Thermodynamics - ISubtopic:First law of Thermodynamics
⏱ 2mℹ️ Source: PYQ_2020

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