页数：58页文件大小：4.57 MB来源： Atkins’PhysChem物理化学ppt课件
本课件先读液-液部分互溶与液-固相图，包括低共熔体系、区域熔炼与生成化合物的体系；随后转入化学平衡，用反应吉布斯自由能给出平衡判据与反应进度、平衡组成的关系。
Phase Transformations Phases, Components and Degrees of Freedom Definitions The Phas
Phase Transformations Two - Component Systems Vapour Pressure Diagrams Composition o
Temperature - Composition Diagrams Distillation of Mixtures Azeotrope s Immiscible L
Liquid - Liquid Phase Diagrams Liquid - Solid Phase Diagrams Eutectic s Phase Separa
8.5 Liquid - Liquid Phase Diagrams Partially miscible liquids are liquids that do not mix in all proportions at all temperatures When P = 2, F’ =
Hexane and Nitro benzene system Mixture of 50 g hexane (0.59 mol C 6 H 14) and 50 g nitro benzene (0.41 mol C 6 H 5
Hexane and Nitro benzene system Ratio of amount of each phase: There is 7 times as much nitro benzene rich phase as
(b) Critical Solution Temperatures The upper critical solution temperature, Tuc, is the highest temperature at which ph
(b) Critical Solution Temperatures Gibbs energy of mixing varies with T – double minima indicate partially miscible pha
(b) Critical Solution Temperatures The lower critical solution temperature, Tlc, is the lowest temperature at which pha
(b) Critical Solution Temperatures Some systems have both TucandTlc, with a famous example being nicotine in water, whe
(c) The distillation of partially miscible liquids Consider a partially miscible liquid formed a low - boiling azeotrope. Both properti
(c) The distillation of partially miscible liquids Two liquids become fully miscible before they boil. a 1: P = 1, liquid a 2: P = 2, l
(c) The distillation of partially miscible liquids Two liquids boil before they are fully miscible. a 1: P = 1, liquid a 2: P = 2, liqu
(c) The distillation of partially miscible liquids a 1: P = 1, x B = 0.95 a 2: 350 K, P = 2, x B = 0.95, 0.66 a 4: 320 K, P = 3, x B =
8.2 Liquid - Solid Phase Diagrams Solid and liquid phases can be present below the boiling point (e. g., immiscible pa
8.6 Liquid - Solid Phase Diagrams 2 - component liquid at temperature a 1 a 1 a 2: System enters “ L i q + B ” pure
(a) Eutectic s Liquid with eutectic composition freezes at a single temperature, Te, without deposi
(a) Eutectic s Solder 67 % t in and 33 % lead, m. p. 183 o C 23 % NaCl, 77 % H 2 O m. p. - 21.1 o C
(a) Eutectic s 在化工生产和科学研究中常要用到低温浴，配制合适的水- 盐体系，可以得到不同的低温冷冻液。例如：水盐体系低共熔温度252 K 218 K 262.5 K 257.8 K
Eutectic formation and thermal analysis Eutectic formation happens in many binary alloy systems, important in alloy microstr
s (A) + s (B) ls (A) + ls (B) Ls (A) l + s (B) cabde
Eutectic formation and thermal analysis
p = 101325 Pat / ℃
(b) Reacting Systems System prepared with A (G a) and excess of B (As) consists of C (G a As) and unreact
(b) Reacting Systems Solid deposited along the cooling is opleth “ a ” is compound C The binary B, C syst
(b) Reacting Systems A complex diagram combined from three simple one. at given pressure t / ℃ ABCE 1 E 2
(c) Incongruent Melting (1) a 1 → a 2, liquid + K / N a Sometimes component C is not stable as a liquid (all
(c) Incongruent Melting Sometimes component C is not stable as a liquid (alloy N a 2 K) Incongruent melting:
(c) Incongruent Melting
A complex diagram combined from three simple one.
A complex diagram combined from three simple one.
Preparing ultra pure materials Completely miscible solid solutions 区域熔炼（zone melting
Completely miscible solid solutions 枝晶偏析固- 液两相不同于气- 液两相，析出晶体时，不易与熔化物建立平衡，较早析出的晶体含高熔点
Completely miscible solid solutions 淬火（quenching）为了使固相合金内部组成更均一，就把合金加热到接近熔点的温度，保持一定时
(d) Applications ClNO 2 ClNO 2 ClClNO 2 HNO 3 + H 2 SO 4 w = 0.33 w = 0.01 w = 0.66 如何分离？ Physical co
(d) Applications 送往精馏塔送往精馏塔分离出对硝基氯苯混合液分离出邻硝基氯苯精馏釜底液送往A 结晶器进入B 结晶器l + s
(d) Applications 结晶法精制盐类例如，将粗盐精制。首先将粗盐溶解，加温至353 K，滤去不溶性杂质，设这时物系点为S。冷却至Q 点，有精盐析出。继续降温至R 点（R 点尽可能接近三相线，
Chemical Equilibrium Chapter 9
Spontaneous chemical reactions The response of equilibria to the conditions Ho
Spontaneous chemical reactions 9.1 The Gibbs energy minimum (a) The reaction Gibbs energy A B d ξ A B dnA = - d ξ dnB = d ξ ξ: the ext
(a) The reaction Gibbs energy Spontaneous μ A > μ B Δ r G < 0 d G = μ A dnA + μ BdnB = - μ A d ξ + μ B d ξ =
(b) Exergonic and endergonic reactions Reverse spontaneous Δ r G > 0 endergonic reactions At equilibrium Δ r G = 0 Sp
9.2 The description of equilibrium Δ r G = Δ r G + RTlnpB / p A = Δ r G + RTlnQQ = p B / p A Δ r G = G B,
(b) The general case of a reaction μ J = μ J + RTlnaJ For a reaction: a A + bB cC + dDdG = Σ μ JdnJ = (Σ ν J
(b) The general case of a reaction For a reaction: a A + bB cC + dD
(b) The general case of a reaction For a reaction: H 2 O (g) H 2 (g) + ½ O 2 (g) Δ G = 118.08 k J mol - 1 at 23
(b) The general case of a reaction O 2 H 2 H 2 O 00 n Initial amount ½ α n α n - α n Change to reach eqm ½ α n α
(b) The general case of a reaction For a reaction: H 2 O (g) H 2 (g) + ½ O 2 (g) About 2 % of water has decompo
(c) The relation between equilibrium constants For a reaction: A + B C + D
(c) The relation between equilibrium constants The composition of gases mixture can be written as： p J、c J、yJThenK can be wri
(c) The relation between equilibrium constants When Σ ν J = 0, K = K p = K c = Ky = K n
(d) Equilibria in biological systems As we saw before that the biological standard state is pH = 7, for a reaction:
Exercises (a) 8.14, 15,17, 9.7 Discussion: problems 8.15 Homework
下载地址：{{downurl}}
{{{a}}}
{{#b}}{{{b}}}
{{/b}} {{/title}} {{#nolog}}登陆注册
{{/nolog}} {{#djsx}}点我刷新
{{/djsx}} {{#gocz}} {{/gocz}} {{#ffqr}} {{/ffqr}}