第十三章p區(qū)元素（二）

1、2024/3/28,劉曉瑭,1,無機化學,2010級應用化學專業(yè)劉曉瑭E-mail：xtliu@scau.edu.cnTel： 85280325Blog：http://www.sciencenet.cn/u/jlxt33,本章要求：１、熟悉氧化物的分類。２、掌握臭氧、過氧化氫的結構、性質和用途。3、掌握SO2、SO3、亞硫酸、硫酸和它們相應的鹽、硫代硫酸鹽、過二硫酸鹽等的結構、性質、制備和用途以及它們之間的相互轉化關系

2、4、掌握無機酸強度的變化規(guī)律。重點：過氧化氫;硫的氧化難點：硫的氧化物的結構學時：3,9 氧族元素Oxygen Family Elements,2024/3/28,劉曉瑭,3,目 錄,9.1氧族元素的通性9.2 氧9.3 硫和硫化物9.4硫的含氧化合物9.5硒和碲,硫的成鍵特征 S：3s23p43d0 1 離子鍵：如Na2S、CaS、(NH4)2S等。 2 共

3、價鍵： (1) 共價單鍵，H2S、SCl2 ； (2) 共價雙鍵，CS2； (3) 3d成鍵，SOCl2、SF4、SO3、SF6等。 3 多硫鏈：－Sn－ 長硫鏈。 過硫化物Na2S2、FeS2、H2S2、S2Cl2，多硫化氫H2Sn (硫烷)、多硫化物MSn和連多硫酸H2SnO6。,硫原子和氧原子成鍵特征的異同點,離子鍵 共價單鍵 重鍵

4、 配位鍵O原子： O2- -O- O= O≡O O←S原子： S2- -S- S= ← S,形成離子鍵的能力較弱,主要形成共價單鍵,形成重鍵的能力較弱,可以給出電子對形成配鍵,硫原子半徑較大，變形性大，以共價單鍵為主要成鍵特征。它的另一個成鍵特點是S原子間可以形成硫鏈：-S-S-S-S-,2024/

5、3/28,劉曉瑭,6,9.3 硫和硫化物,9.3.1 單質硫9.3.2硫化氫和氫硫酸9.3.3硫化物,2024/3/28,劉曉瑭,7,1.單質硫的存在,在自然界中存在天然單質的硫，主要在火山區(qū)，這是因為 2H2S + SO2 = 3S↓ + 2H2O 2H2S + O2 = 2S↓ + 2H2O 反應物中的H2S來自地下硫化物礦床與高溫水蒸汽的反應。,單斜硫,斜方硫,彈性硫,升華硫,2

6、 單質硫的結構,S以sp3雜化形成環(huán)狀S8分子,(1) S8：最穩(wěn)定的形式，成環(huán)狀或皇冠狀。 它有兩種形式： 斜方硫(orthorhombic) 呈黃色； 單斜硫（nonoclinic）呈淺黃色。 (2) 同素異形體的轉化 S2是順磁性的，而S4 , S6 , S8 ……都是反磁性的,2024/3/28,劉曉瑭,9,Charles Goodyear Charles Goodyear (1800-1860)

7、, American inventor, experimented with, perfected, and promoted the use of vulcanized rubber. He was instrumental in establishing the rubber industry in the United States.Charles Goodyear was born on Dec. 29, 1800, in

8、New Haven, Conn. He attended the local public schools. His father was an inventor, manufacturer, and merchant of hardware, especially of farm tools. When Charles was 17, his father sent him to Philadelphia to learn the b

9、usiness, and at 21 he returned to become his father's partner. He married at the age of 24 and 2 years later opened a store in Philadelphia. In 1830 a lifetime of financial distress began for the Goodyears when both

10、father and son went bankrupt.On a trip to New York City that year, Goodyear visited a store that sold goods made of india rubber, a product only recently manufactured in America. Inspired by the possibilities of the mat

11、erial, he determined to improve its usefulness. His first experiments were carried out in jail, where he had been sent for failure to pay his debts.In 1837 Goodyear settled his family on the charity of friends near New

12、Haven and went to New York to continue his work. He received a patent for an improved type of rubber and was able to find a modest amount of financial backing. After moving to Massachusetts, he met Nathaniel M. Hayward,

13、an inventor, whose patent on a process for mixing sulfur with rubber he bought. Goodyear intended to combine the new patented process with his old one, which involved coating rubber with an acid and metal.During an argu

14、ment one day in his shop, Goodyear accidentally dropped a piece of the sulfur-impregnated rubber on a hot stove. Instead of melting, it merely charred slightly. Realizing the importance of this (two major drawbacks to us

15、ing rubber were that it melted at high temperatures and tended to harden at low temperatures), he began experiments to discover the proper proportions and method of baking the new type of rubber, which he called "vu

16、lcanized." His critical patent was issued on June 15, 1844, after he had borrowed $50,000 for experiments, little of which was ever repaid. He claimed to have found more than 500 uses for rubber and received patents

17、 in all countries except England, where Thomas Hancock had invented vulcanization in 1843. When Goodyear died in 1860, he left his wife and six children $200,000 in debt.,3. 單質硫的物理性質,彈性硫的形成實驗,硫的相對粘度與溫度的關系,當溫度升高時，S8環(huán)斷裂形成

18、鏈狀分子，粘度增大，顏色變深。,溫度約473K時粘度最大，再升高，則長鏈斷裂為小分子粘度變小，顏色變淺。,4. 硫的化學性質,硫在空氣中燃燒,2024/3/28,劉曉瑭,16,9.3 硫和硫化物,9.3.1 單質硫9.3.2硫化氫和氫硫酸9.3.3硫化物,3. 硫化氫的性質,其還原性體現(xiàn)在：,2024/3/28,劉曉瑭,21,9.3 硫和硫化物,9.3.1 單質硫9.3.2硫化氫和氫硫酸9.3.3硫化物,② 硫化物的

19、難溶性 許多金屬離子在溶液中與硫化氫或硫離子作用，生成溶解度很小的硫化物。,2. 重金屬硫化物,① 硫化物的顏色 大多數(shù)為黑色，如FeS、CoS、NiS、Ag2S、CuS、HgS(也有紅色的HgS)、PbS等。 少數(shù)為其它顏色，如 ZnS白色，MnS淺粉色，CdS、SnS2黃色，Sb2S3、Sb2S5橙色，SnS褐色。,Image of fluorescence in various

20、sized Cadmium Selenide Quantum Dots.,Photoluminescence of Quantum Dots,2024/3/28,劉曉瑭,34,2024/3/28,劉曉瑭,35,目 錄,9.1氧族元素的通性9.2 氧9.3 硫和硫化物9.4硫的含氧化合物9.5硒和碲,2024/3/28,劉曉瑭,36,9.4硫的含氧化合物,9.4.1 硫（Ⅳ）的含氧化合物9.4.2 硫（Ⅵ）的含氧化合物

21、9.4.3 硫的其他氧化態(tài)的含氧化合物,ⅣⅥ,(1) SO2的結構 S：sp2雜化，∠OSO＝119.5°，S－O鍵長143.2 pm SO2是極性分子,1. SO2,ⅣⅥ,2024/3/28,劉曉瑭,43,9.4硫的含氧化合物,9.4.1 硫（Ⅳ）的含氧化合物9.4.2 硫（Ⅵ）的含氧化合物9.4.3 硫的其他氧化態(tài)的含氧化合物,ⅣⅥ,β型晶體：石棉鏈狀結構 (SO3)n 分子

22、，是由SO4四面體連成一個無限長鏈分子。,2. 硫酸,(2) 濃H2SO4的性質,(3) 硫酸鹽(正鹽和酸式鹽),● 硫酸鹽的性質,③ 易形成復鹽 復鹽是由兩種或兩種以上的簡單鹽類所組成的結晶化合物，常見的組成有兩類： ● M2ⅠSO4·MⅡSO4·6 H2O： MⅠ：NH4＋, Na＋, K＋, Rb＋, Cs＋； MⅡ：Fe2＋

23、, Co2＋, Ni2＋, Zn2＋, Cu2＋, Hg2＋； 如摩爾鹽 (NH4)2SO4·FeSO4·6 H2O 鎂鉀礬 K2SO4·MgSO4·6 H2O。,● MⅠSO4· M2Ⅲ(SO4)3·24 H2O： MⅢ：V3＋, Cr3＋, Fe3＋, Co3＋, Al

24、3＋, Ga3＋ 等， 如明礬 K2SO4·A12(SO4)3·24 H2O、 鉻礬 K2SO4·Cr2(SO4)3·24 H2O。,硫酸鹽分解與溫度的關系為： 同族，等價金屬硫酸鹽的熱分解溫度從上到下升高: MgSO4 (895 ℃)＜CaSO4 (1 149 ℃)＜SrSO4 (1 374 ℃)

25、 若同種元素能形成幾種硫酸鹽，則高氧化態(tài)硫酸鹽 的分解溫度低: Mn2(SO4)3 (300 ℃)＜MnSO4 (755 ℃) 若金屬陽離子的電荷相同、半徑相近，則 8e 構型比18e 構型的陽離子硫酸鹽的分解溫度要高： CdSO4 (816 ℃) ＜ CaSO4 (1 149 ℃),2024/3/28,劉曉瑭,58,9.4硫的含氧化合物,9.4.1

26、 硫（Ⅳ）的含氧化合物9.4.2 硫（Ⅵ）的含氧化合物9.4.3 硫的其他氧化態(tài)的含氧化合物9.4.4 硫的含氧酸的衍生物,ⅣⅥ,3. 連二亞硫酸及其鹽,（1）結構,Na2S2O4 . 2 H2O是染料工業(yè)上常用的還原劑，稱為保險粉。,（2）制備和性質,小 結,2024/3/28,劉曉瑭,71,9.4硫的含氧化合物,9.4.1 硫（Ⅳ）的含氧化合物9.4.2 硫（Ⅵ）的含氧化合物9.4.3 硫的其他氧化態(tài)的含氧化合

27、物9.4.4 硫的含氧酸的衍生物,ⅣⅥ,1. 酰鹵,2. 鹵磺酸,附錄： 硫的鹵化物,硫的氮化物（sulfur-nitrogen compounds）,2024/3/28,劉曉瑭,80,目 錄,9.1氧族元素的通性9.2 氧9.3 硫和硫化物9.4硫的含氧化合物9.5硒和碲,2024/3/28,劉曉瑭,81,9.5 硒和碲,9.5.1 單質9.5.2 硒和碲的氫化物9.5.3 硒和碲的含氧化合物,2024/3/

28、28,劉曉瑭,83,9.5 硒和碲,9.5.1 單質9.5.2 硒和碲的氫化物9.5.3 硒和碲的含氧化合物,H2Se、H2Te的水溶液是氫硒酸和氫碲酸。25℃，1×105 Pa下飽和溶液中，H2Se的濃度為 0.084 mol·L－3，H2Te為 0.09 mol·L－3 (H2S為 0.1 mol·L－3)，其酸性均比H2S強。其次序為： H2Se Ka1

29、θ＝1.29×10－4 Ka2θ ＝1.0×10－11 H2Te Ka1θ＝2.3×10－3 Ka2θ＝1.6×10－11 比較： H2S Ka1θ＝1.07×10－7 Ka2θ＝1.26×10－13,2024/3/28,劉曉瑭,86,9.5 硒