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Heat influx into a system should inrease entropy→ true

Heat influx into a system should inrease entropy→ true

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16:08 Heat influx into a system should inrease entropy  true Thermal Disorder: Positional disorder: Carnot suggests: q(H)/T(H) + q(L)/T(L) = 0 q/T is a state function Clausius:    (1/T)dq is a state function S = S(f) – S(i) S =   dq(rev)/T S (sys) for isothermal process S=q(rev)/T Compression/ Expansion of gas If …. q(rev)= nRT ln (V2/V1) Then  …. S=nR ln (V2/V1) When volume is expanded, S increases Phase Transition q (rev) =  H (fus) q (rev) =  H (vap) q (rev) =  H (sub) Determine melting point or freezing point using enthalpy and Heat S (fus) =  H (fus)/Tf      in which Tf= freezing or melting Temperature S (sub) =  H (sub)/Tf
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Determine Boiling point S (vap) =  H (vap)/Tb All liquids have the same  S = 88+/-5 J/mol-K
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Unformatted text preview: Trouton’s Rule What happens to ∆ S if T changes: ∆ S = ∫ (b to A) 1/T dq(rev) Adiabatic = Heat doesn’t change q=0 so ∆ S=0 isentropic Isochoric (volume doesn’t change) : dq(rev) = nC(v)dT ∆ S = ∫ (T2 to T1) nC(v)/T dT ∆ S = nC(v) ln (T2/T1) at constant V ∆ S = nC(p) ln (T2/T1) at constant P Entropy always increases as temperature increases What if we have two systems? Both at same ∆ T One at constant V , one at constant P C(p) > Cr ∆ S(p)> ∆ S(r)v Now consider about the surroundings :- treat surrounding as a big heat sink, temperature doesn’t change much in surroundings, because it’s too big 16:08 16:08...
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