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主族 (Main groups)

主族 (Main groups). The members of a group have analogous valence-shell electron configurations . The element at the head of a group often has a character that is quite distinct from the other members of the group.

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主族 (Main groups)

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  1. 主族(Main groups) • The members of a group have analogous valence-shell electron configurations. • The element at the head of a group often has a character that is quite distinct from the other members of the group. • There are diagonal relationships between elements, especially between Periods 2 and 3. • There is a trend toward metallic character on going to the left along a period and on going down a group.

  2. 元素的性质 • He-Rn， 天然存在形式, 单原子气体；Ar, the 3rd most abundant gas in the atmosphere (after N2, O2); He, the 2nd abundant element in the universe after H, rare on Earth. A component of natural gases (notably Texas) • He, Buoyancy in airships; dilute O2; coolant; He-Ne lasers. Cryogenics, superfluidity (<2K); Only substance known to have more than one liquid phase. • Ne, emits a red glow when an electric currents through it. • Ar, provide an inert atmosphere. (light bulbs) • Kr, intense white light, airport runway lighting. • Xe, in halogen lamps. Anesthetic (麻醉剂)

  3. Ne+(Ar) Ne Ne: advertising signs; Ar: in some light bulbs (导热) Kr: airport runway lighting; Xe: in halogen lamps for (intense white light) automobile headlights

  4. 电离能

  5. Xe-F Xe + PtF6 → XePtF6 (1962) KrF2; Ke-N (1988, stable below –50ºC) XeF2, XeF4, XeF6 Powerful fluorinating agents Pt(s) + XeF4(s) → Xe(g) + PtF4(s)

  6. Crystals of XeF4

  7. Only xenon is known to form en extensive series of compounds with fluorine and oxygen. Xenon fluorides are powerful fluorinating agents, and xenon oxides are powerful oxidizing agents.

  8. 卤素 Halogen (“成盐”)

  9. I2, Br2, Cl2

  10. 分子轨道理论  F2, Cl2, Br2, I2, 最大吸收波长 长， 减小

  11. 电负性

  12. 增 电负性数据 减

  13. 原子和离子半径

  14. 元素的性质(F, Cl) • F， 天然存在形式, CaF2, Na3AlF6, Ca5F(PO)3 • F2, 最强的氧化剂，Eo = +2.87 V, 电解(KF+HF) 5×106 Kg / y in US, UF6 (volatile solid), processing 核燃料；SF6, electrically insulating gas; Fluorinated hydrocarbons, Teflon, Freon(氟利昂), they are inert. 大多数氟化物溶解性 低(除AgF)，尽管其丰度比Cl大。 • Cl2， 电解NaCl(pale yellow-green gas) • It reacts directly with nearly all the elements (除C,N,O, noble gases ). 强的氧化剂, 氧化金属到高氧化态，如： 2Fe(s) + 3Cl2 → 2FeCl3(s) → 塑料，溶剂，杀虫剂; 漂白纸，纺织品；水消毒 2004年7月8日，美国环保署(EPA)宣布，杜邦公司由于在过去的20多年来从未通报特富龙制造过程中的一种成分——全氟辛酸铵可能对人体有害，已经违反了毒物管制法，决定对其处以3亿美元的巨额罚款。

  15. HF + KF = KHF2, 2KHF2 = 2KF + H2 + F2

  16. 电解池 2NaCl(aq)+2H2O(l)=2NaOH(aq)+Cl2(g)+H2(g) 阴极 还原H+到H2 阳极 氧化Cl-到Cl2 阳极 氧化F-到F2 阴极 还原H2O到H2

  17. 2Fe(s) + 3Cl2 → 2FeCl3(s)

  18. 2Br-(aq) + Cl2(g) → Br2(l) + 2Cl-(aq)

  19. 元素的性质(Br, I) • Br2, 腐蚀性红棕色冒烟液体 • 有机合成中，加溴和去溴 • I2， 海藻2000 Kg → 1 kg I2 Cl2(g) + 2I-(aq) → I2(aq) + 2Cl-(aq) 易升华，固态I2分子仍为孤立分子，不象C,Si,P,S那样形成原子链或网。 (I2+KI+乙醇), 碘酒，消毒杀菌 碘缺乏症(swelling of the thyroid gland in the neck)

  20. I2的溶液：CCl4, H2O, KI, 淀粉+KI

  21. The picture above shows the result of touching nitrogen triiodide (NI3)! Nitrogen triiodide is percussion (碰击) sensitive.

  22. 互卤化物 Cl2(g) + 3F2(g) → 2ClF3(g) Cl2(g) + 5F2(g) → 2ClF5(g) 物性：介于两种单质之间； 化性：取决于X-X’键能 (X heavier, decreasing)

  23. 价层电子对互斥理论

  24. H2(g) + X2(g) → 2HX(g) CaF2(s) + 2H2SO4 (aq, conc) → Ca(HSO4)2(aq)+ 2HF(g) KI(s) + H3PO4 (aq) →KH2PO4(aq)+ HI(g) 氢键

  25. (HF + NH4F) frosts the glass surface SiO2(s) + 4HF(aq) → SiF4(g) + 2H2O(l) Go = -12.0kJ/mol HF具有强腐蚀性！

  26. 解离能 电子亲核能 升华热 + 电离能 生成焓 晶格能 晶格能 生成焓 离子型氯化物的生成焓和晶格能

  27. 含氧酸 高 (正) 亚 次 非羟基氧数目，酸性

  28. HX(I)O .. .. :Cl-O-H .. .. Cl2(g) + H2O(aq) → HClO(aq) + HCl(aq) unstable Cl2(g) + 2OH-(aq) → ClO-(aq) + Cl-(aq) + H2O(l) ClO-— Cl2 — Cl- 0.40 V 1.36 V Cl2(g) + CaO(s) (生石灰) → Ca(ClO)2 净化游泳池水 (“84”消毒液主要成分：NaClO)

  29. 注意： 一般来说, E3  E2– E1 G具有加合性，而 E不具加合性，为强度量。 元素电势图： 将同一种元素的不同物种，按氧化态从高到低的顺序排列，两物种间用横线相连，将其对应电对的E标注在横线上面。 0.52 E2 0.54 0.44 EB(V): BrO3-——— BrO-——— Br2 E1 E3 (+5) (+1) (0)

  30. 0.34 E3 例： 0.16 0.52 EA(V): Cu2+——— Cu+——— Cu E1 E2 若 E右 >E左 时， 发生歧化反应 2 Cu+＝ Cu2+ + Cu

  31. HX(V)O3， HX(VII)O4 3Cl2(g) + 6OH-(aq) △→ ClO3-(aq) + 5Cl-(aq) + 3H2O(l) 分解 4KClO3(s) △ → 3KClO4(s) + KCl(s) 2KClO3(s) △(MnO2) → 2KCl(s) + 3O2(g) 氧化剂(焰火，火柴) 2NaClO3(aq) + SO2(g) + H2SO4(aq) → 2NaHSO4(aq) + 2ClO2(g) (paramagnetic yellow gas, 漂白纸浆) ClO3-(aq) +H2O(l) → ClO4-(aq) + 2H+(aq) + 2e- HClO4, 无色液体，最强酸。Powerful氧化剂，爆炸！

  32. Frost (or Latimer) diagram display the same information but in a different way. When interpreting electrode potential data, either in numerical or graphical form, it is important to remember that a single potential in isolation has no meaning! The perhalic acids and their anions are strong oxidizing agents. They do, however, have considerable kinetic stability.

  33. The interhalogens (互卤化物) have properties intermediate between those of the constituent halogens. Nonmetal form covalent halides; metal form ionic halides. (共价与离子型卤化物) The oxoacids of chlorine are all oxidizing agent. Acidity and oxidizing strength of oxoacids both increase as the oxidation number of the halogen increase. (含氧酸的酸性与氧化性)

  34. 氧(硫)族 Chalcogen (“成矿”)

  35. 23% of the mass of the atmosphere Liquid oxygen is pale blue (<-183ºC) The gas is colorless. Paramagnetic 2 ×1010 kg LO2/y (US) Ca. 80kg/person Steel industry 光解水： 2H2O(l) →2 H2(g) + O2(g) 光合作用： 6CO2(g) + 6H2O(l) → C6H12O6(s) + 6O2(g)

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