IMG_0001_NEW_0014 - a state can be achieved (# of...

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Entropy and States of Matter Melting ffi * 3€s"8 Ssolid < Stiq,.'ia More available space + More microstates = Less likely to be ordered = Increased Entropy Vaporization to Xdc+o ( "e o oo Sriquio Dissolving 6 ^^O .)crr ^ ^L) OOXXO_ ffi 36'8€^ -+ 3d'f^$ry" o'o%' S(rol,r"nt + solute) Entropy increases when: 1. Pure liquids or liquids solutions are formed from solids 2. Gases are fomed from either solids or liquids 3. The number of molecules of gas increases as a result of a chemical reaction .1. The temperature increases (increase number of accessible energy levels) s --. .-l Change in Entropy and Gas Expansion (o) -\S : k, h1 Q7;,,i - kuhQ,,,,,u,: ko h[ " ] Change in entropy when gas expands into 2 x volume (Vrnrr : 2 * Vin,,,u,) Single gas molecule: \t.trc I Double the number of positions available - Qi,n.t :2 x Q,n,tiu, : double microstates for entropy: Len"Z Giving Entropy a Value Statistical interpretation of entropy Qualitatively: Entropy: number of ways
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Unformatted text preview: a state can be achieved (# of microstates) State with highest probability has highest entropy Quantitatively: Boltzmann's Equation S=frakrf) kB: MNA: Boltzmann's constant : 1.3907 10-23 J.K-r f) : number of microstates corresponding to a given state of the system (defined by position and energy) l\'at ur e spo nt ane ous ly pro c e e ds t ow ar ds states with highest probabilities of existing l0 AS for Gas Expansion Change in entropv rvith change in volume . For gas molecules experiencing a change in volume: Vini,i&quot;l J Vfi.d . Change in possible microstates cc Change in voiume r) :l-al &quot;final &quot; '&quot;initial a) o tnllat l'nnul Boitzmann' h,f ?q'l= I, f), / s equatlon x. ln2 Gives value lor change in entropv rvith change in volLrme Units for AS = J.K-r = 1.)tu-l ylo lJ -- 1 91 rp-a 7 ye f-l,,'nu&quot;u,'f-_l Vin&quot;t -I l-l t&quot;-/ v- -tnlltil =&quot;^^(?) AS,. ,. LqA md!tt^&amp; z x -{le( i...
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This note was uploaded on 12/27/2011 for the course CHEM 122 taught by Professor Williams during the Fall '10 term at Simon Fraser.

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