三点说明①当△G.数值较大时，可用△G.代替△G.估计/判断反应方向。[△,Gm>41.84KJ/mol②当△G㎡数值较小时，△，Gm<40KJ/mol，需用化学反应等温式计算出△Gm，用△G的符号判断方向。③当△G.=0时，反应达平衡，由化学反应等温式△,G.=-RTInQ=-RTInK°：一定温度下，一确定反应，其△G.是个定数：此时Q为一常数，称之为标准平衡常数，用K表示。显然同样类型的反应，相同温度时，K越大，表明反应正向进行的程度越大
三点说明 ① 当△rGm º数值较大时，可用△rGm º代替△rGm估计 / 判断 反应方向。 |△rGmº| > 41.84 KJ/mol ② 当△rGm º数值较小时，|△rGmº| < 40KJ/mol，需用化学反 应等温式计算出△rGm，用△rGm的符号判断方向。 ③ 当 △rGm = 0时，反应达平衡，由化学反应等温式 △rGm º=－RT㏑Q = －RT㏑Kº ∵一定温度下，一确定反应，其△rGm º是个定数 ∴此时Q为一常数，称之为标准平衡常数，用Kº表示。显然， 同样类型的反应，相同温度时，Kº越大，表明反应正向进行 的程度越大
2.Chemicalequlibrium2.1 Characteristics of an equilibrium2.2Equlibrium constants and equlibriumconstantexpressions: K, K, Kp2.3Transfer rate平衡转化率α=(C初一C平)/C初=△C/C初3. Shifts in chemicalequilibium3.1Effect of changes in concentrations3.2 Effectofchanges inpressure3.3 Effectof changes in temperature3.4Effectofcatalyst
2.Chemical equlibrium 2.1 Characteristics of an equilibrium 2.2 Equlibrium constants and equlibrium constant expressions：Kº, Kc , Kp 2.3 Transfer rate平衡转化率 α= (C初－C平) / C初 = △C / C初 3. Shifts in chemical equilibium 3.1 Effect of changes in concentrations 3.2 Effect of changes in pressure 3.3 Effect of changes in temperature —— 3.4 Effect of catalyst
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Each component concentration will not change withtime. Although different initial concentrations give differentequilibium concentrations, the quantity, [H]’eq/ [H,leql] eq,is constant.K,=[H]2e/ [H,leq[leqTheconstant is called equilibrium constant for theequilibrium and is reprensented bythe symbol Kc. Dynamic equilibrium. The forward reaction rate equalsto thereverse reaction rate10It is a conditional eguilibrium.When the concentration.pressure and temperature change, the equilibrium positionwill change
u Each component concentration will not change with time. Although different initial concentrations give different equilibium concentrations, the quantity, [HI]2 eq/ [H2 ] eq[I2 ] eq, is constant . Kc = [HI]2 eq/ [H2 ] eq[I2 ] eq The constant is called equilibrium constant for the equilibrium and is reprensented by the symbol Kc. • Dynamic equilibrium. The forward reaction rate equals to the reverse reaction rate. It is a conditional equilibrium. When the concentration, pressure and temperature change, the equilibrium position will change
2.2Equlibrium constants andEqulibrium constant expressions: K°, K,, KaA+bB=gG+hH2.2.1Experimental equilibrium constants(1)Concentration equilibrium constants K[G][H]K[A][B]C: mol/L
2.2 Equlibrium constants and Equlibrium constant expressions：Kº，Kc，Kp aA + bB = gG + hH 2.2.1 Experimental equilibrium constants (1) Concentration equilibrium constants Kc a b g h A B G H Kc = C: mol/L