1.27k likes | 1.61k Views
Ch.45 – Transition metals Ch.45 – 過渡金屬 . General features of d-block elements d- 棟元素的一般性質 1. Meaning of transition elements 過渡元素的意思 * First transition series : 第一列過渡元素: . Sc. Fe. Co. Ni. Cu. Zn . Ti . V. Cr. Mn.
E N D
Ch.45 – Transition metals Ch.45 –過渡金屬
General features of d-block elements • d-棟元素的一般性質 • 1. Meaning of transition elements 過渡元素的意思 • * First transition series : 第一列過渡元素: Sc Fe Co Ni Cu Zn Ti V Cr Mn
* Electronic configurations of elements in first transition series : * 第一列過渡元素的電子組態: At. no. Name Inner shell 3d 4s 21 Scandium 1s 2s 2p 3s 3p 2 2 6 2 6 22 Titanium 1s 2s 2p 3s 3p 2 2 6 2 6 23 Vanadium 1s 2s 2p 3s 3p 2 2 6 2 6 24 Chromium 1s 2s 2p 3s 3p 2 2 6 2 6 25 Manganese 1s 2s 2p 3s 3p 2 2 6 2 6
26 Iron 1s 2s 2p 3s 3p 2 2 6 2 6 27 Cobalt 1s 2s 2p 3s 3p 2 2 6 2 6 28 Nickel 1s 2s 2p 3s 3p 2 2 6 2 6 29 Copper 1s 2s 2p 3s 3p 2 2 6 2 6 30 Zinc 1s 2s 2p 3s 3p 2 2 6 2 6
21 Scandium 1s 2s 2p 3s 3p 2 2 6 2 6 22 Titanium 1s 2s 2p 3s 3p 2 2 6 2 6 23 Vanadium 1s 2s 2p 3s 3p 2 2 6 2 6 24 Chromium 1s 2s 2p 3s 3p 2 2 6 2 6 25 Manganese 1s 2s 2p 3s 3p 2 2 6 2 6 * The d-block element is so called because its members have atoms with electronic configurations in which the d- orbitals are being filled. * d-棟元素是指其成員原子之電子組態正在填入d-軌態。
* Sometimes, d-block elements or transition elements are also defined as elements which form compounds in which there is an ______________ ________ subshell of d electrons in at least one of its compounds. (Such definition effectively excludes scandium and zinc from the list of transition elements.) incompletely filled * 有時,d-棟元素或過渡元素可定義為至少有一個化合物擁有__________的d亞層。(如此定義則排除了鈧和鋅。) 不全滿
2. Transition elements as metals * d-electrons are involved in the metallic bond formation in the case of transition metals, therefore they have metallic bond than s-block metals. Such characteristics make transition metals extremely useful as structural metals. stronger 2. 過渡元素作為金屬 * 過渡金屬形成金屬鍵涉及d-電子,所以它們的鍵比s-棟金屬_______。此特性使過渡金屬有利於作為建築用的金屬。 較強
* The _______________________ of the transition metals make it possible for atoms of one element to replace those of another element in the formation of alloys . It is possible to make alloys containing transition elements in a wide range of composition. similar sizes * 過渡金屬的原子彼此___________,使它們可以互相替代而形成合金。過渡元素的合金組成可以有很闊的範圍, 大小相若
The solid structure is slightly deformed but this is sufficient to modify the physical properties of the structural material, e.g., manganese is well-known for conferring hardness and wear resistance to its alloys, and chromium is responsible for conferring passivity on stainless steels. 其固體結構被輕微扭曲,這足而把這些建築用的金屬之物理性質改良,e.g., 眾所周知,錳可賦予其合金硬度及抗磨損度,鉻則賦予不銹鋼的抗腐蝕性。 Mn Cr
* Some uses of transition metals 某些過渡金屬的用途 • q Titanium is used in the construction of the hull of the space shuttle and aircraft • q鈦用於建造穿梭機及太空船的外殼。
q Coinage metal is an alloy of copper and nickel. q鑄幣金屬乃銅及鎳合金。
q The bumpers of vehicles are chromium plated, giving shiny appearance. q汽車的保險槓鍍上鉻而帶來光澤。
q Pure titanium is not rejected by the body and has been used in replacing missing human teeth with great success. q純鈦不被人體排斥故可成功地用作假牙。
qCopper is used for cooking ware, electrical cables and water pipes. • 銅可用作煮食器皿、電線及水管。
Tsing Ma Bridge is constructed of steel Iron is used to make ships • q Iron is the most important structural metal ever used • 鐵是一直而來最重要的建築金屬。
3. Comparison of some properties of d-block and s-block metals 3. 比較d-棟及s-楝金屬的性質
a) Atomic radii * Variation of atomic radius with atomic number : a) 原子半徑 * 原子半徑隨原子序的變化:
* Two features : (1) d-block metals generally have atomic radii than s-block metals. smaller * 兩項特徵: (1) d-棟金屬原子半徑一般比s-楝金屬________。 較小
(2) d-block metals show considerable _____________ in atomic radius across the series. similarity 相若 (2) d-棟金屬沿週期而過有_________原子半徑。
As one looks at the trend of variation in greater details, it can be seen that the atomic radii of the elements at first ____________ , then remain ____________ in the middle of the series. At the end of the series, the atomic radii actually ____________again. decrease unchanged increase 若仔細看原子半徑的變化,可發現元表的原子半徑起先_______,然後在中段保持______,而在末段則再_____。 下降 不變 上升
At the beginning of the series, the increase in __________ _______________ with atomic number pulls in the electron cloud, resulting in a reduction of atomic size. effective nuclear charge 在週期的開始,_____________隨原子序而增加,把電子雲向內拉而令原子收細。 有效核電荷
Since electrons are added to an inner d subshell across the series, this adds to the primary ______________ and ___________________ of the 3d subshell, so that the effective nuclear charge increases only very slowly in the middle of the row. screening repulsive effect 因著電子加入內層的d-亞層,這增加了d-亞層的____________及_________,所以有效核電荷在中段增加甚小, 屏蔽效應 排斥效應
As a result, there is little change in atomic radii in the middle range. 故原子半徑改變不大。
Towards the end of the series, the screening and repulsive effects of the 3d electrons reach a maximum, resulting in an _______________ of the electron cloud. expansion 在末段屏蔽效應及排斥效應達至高峰,帶來電子雲的__________。 擴大
b) Densities 密度 * Values of densities of s-block and d-block metals d-棟及s-楝金屬的密度 (in g cm-3) M __ Density密度= V
greater * Densities of d-block metals are much than those of s-block metals because (1) d-block metals have ______________ atomic sizes (2) d-block metals have _________________ structures smaller closely packed 高出甚多 * d-棟金屬的密度比s-楝金屬____________,因為 (1) d-棟金屬原子較______。 (2) d-棟金屬有______________結構。 細 緊密裝填
(c)Melting points and hardness熔點及硬度 * Melting points熔點 / ℃
* Melting points and hardness of d-block metals are __________ than s-block metals because (1) the atomic radii of d-block metals are relatively . greater small * d-棟金屬熔點及硬度_________s-楝金屬,因為 (1) d-棟金屬原子半徑較___________。 高於 細
(2) d-block metals usually have a ______________ metallic lattice structure. (3)_______________ electrons (including 4s and 3d electrons) are involved in the metallic bond formation. close packed More (2) d-棟金屬有___________晶格結構。 (3) _____電子(包括4s及3d電子)參與金屬鍵的形成。 緊密裝填 更多
* The first ionization enthalpies of the d-block metals are ___________ than those of s-block metals, since the atomic radii of d-block metals are ____________. greater smaller 高 * d-棟金屬的第一電離焓______於s-楝金屬,因為d-棟金屬原子半徑較______ 細
* The second ionization enthalpies of the d-block metals are ________ than Group I metals but still __________ than Group II metals. greater smaller 高 * d-棟金屬的第二電離焓____於第I族金屬但仍______於第II族金屬。 低
* The third ionization enthalpies of d-block metals are _________ than those of s-block metals, which the electrons are removed from the ___________________. smaller inner shell * d-棟金屬的第三電離焓____於s-楝金屬,因為s-楝金屬須從_______移去電子。 低 內層
* Along the d-block metals, some abnormally high I.E. may be found: (1)First I.E. of _____. (2)Second I.E. of _____ and _____ . (3)Third I.E. of _____. (4)Fourth I.E. of _____. Zn Cu Cr Mn Fe * 沿d-棟金屬,會發現不正常高的I.E. : (1)_____的第一電離焓。 (2)_____及 _____的第二電離焓。. (3)_____的第三電離焓。 _4) ____的第四電離焓。 Zn Cu Cr Mn Fe
e) Electronegativities負電性 * Variation of electronegativities among the s-block metals and the d-block metals : * d-棟及s-楝金屬負電性的變化:
greater * E.N. of d-block metals are______________ than those of s-block metals due to difference in _____________________. effective nuclear charge 高 * d-棟比s-楝金屬負電性_____,這是因為___________的不同。 有效核電荷
f) Reactions with water * s-block metals reacts vigorously with water giving hydrogen gas. d-block metals in general react only very slowly with cold water. f) 與水反應 * s-楝金屬與水劇烈反應產生氫氣。 d-楝金屬一般與冷水只緩慢反應。
* M(s) M(g) Mn+(g) Mn+(aq) d-block metals are less reactive than s-block metals because (1) d-block metals have metallic bond (2) d-block metals have I.E. stronger higher d-楝金屬比s-楝金屬不活潑因為 (1) d-楝金屬有________金屬鍵 (2) d-楝金屬有________I.E. 更強 更高
g) Oxidation state * Except Groups IIIB (e.g. Sc) and Groups IIB (e.g. Zn), all d-block metals exhibit _____________ oxidation states; while this is not the case for the s-block metals. variable g) 氧化態 * 除了第 IIIB族 (e.g. Sc) 及第 IIB 族(e.g. Zn) ,所有d-楝金屬呈現_____氧化態;而這在s-楝金屬是不會出現的。 多變
i) Colour * d-block compounds are often ____________; while s- block compounds are _______________. coloured colourless i) 顏色 * d-楝化合物通常________而s-楝化合物通常______。 無色 有色
Sc Ti V Cr Mn Fe Co Ni Cu Zn + 1 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 4 + 4 + 4 + 4 + 4 + 4 + 4 + 5 + 5 + 5 + 5 + 5 + 6 + 6 + 6 + 7 • Variable oxidation states of d-block elements • B. d-楝元素氧化態的變化 • 1. Oxidation states of the first row transition elements
* Because the 3d and 4s electrons are of ___________ energy, both levels of electrons are available for bonding . There is only a ____________________ in successive ionization energies of the delectrons. similar gradual increase 相若 * 因著 3d 及4s電子能量______,兩階電子均可作鍵合。放此d電子的相繼離子焓只______增加, 逐步
Thus when elements of the first transition series react to form compounds, they can form ions of roughly the ___________________ by losing different numbers of electrons. 所以當它們反應生成化合物時,可以失去不同數目電子以生成___________的離子。 same stability 相若穩定
x o O x x [O= Mn =O] x x - | ‖ O x o x o O O x x x x [O= Cr —O—Cr=O] x x 2- x x | | ‖ ‖ O O * The higher oxidation states arise through ____________ bonding with more electronegative elements such as fluorine, chlorine and oxygen, as in TiCl4 , CrO3 , MnO4-. covalent * 當與較高負電性元素結合,如氟、氯、氧等,會以_______鍵結合達至較高氧化態,e.g. TiCl4 , CrO3 , MnO4- 共價 Cr2O72-: MnO4-:
2. Oxidation states of vanadium * Vanadium forms four important oxidation states in aqueous solution. 2. 釩的氧化態 * 釩在水溶液中有四個重要的氧化態。 +5 +5 +4 +3 +2 Zn Zn Zn VO3-(aq)VO2+(aq) VO2+(aq) V3+(aq) V2+(aq) H+ H+ H+ H+ Red 紅 yellow 黃 blue 藍 green 綠 violet 紫
* Electrode potential values of interconversions between different oxidation states of vanadium: * 釩不同氧化態轉換時的電動勢值: ( ) ( ) ( ) ( ) ( ) +5 +4 +3 +2 0 VO VO V V V 2+ 2+ 3+ 2+ + 1.0 V + 0.36 V - 0.25 V - 1.2 V
* Example: Refer to the following electrode potential – oxidation state chart and electrode potential values.