1、alkali metal,Lithium, Sodium, Potassium, Rubidium and Cesium,The common metals of this group are sodium (2.6% in the lithosphere, NaCl) and potassium (2.4%, KClMgCl2.6H2O, carnallite光卤石). Salt mines are considered to be good places to leave radioactive waste because they are not subject to groundwat 。

2、er flow - that is why the salt got left there in the first place! NaOH, Na2CO3, Na2SO4, Na3P3O9 and Na4SiO4 are among the top 50 industrial chemicals. Potassium salts, notable K2SO4 or KNO3, are an important component of fertilizer. Lithium alkyls are important reagents in synthesis,Na+ and K+ are v 。

3、ery important physiological ions, and Li+ salts are used to treat certain mental disorders. Except Li, the chemistry is predominantly that of the M+ ions. There may be a hint of covalency in certain chelate complexes. Li+ would have a ratio of charge/radius similar to Mg2+ hence certain similarities 。

4、. Other look alikes are NH4+ which is similar to K+ and Tl+ which is a bit like Rb+ or Ag,How do the alkali metals react with water,Reactions of the elements with water,Group 1: M(s) + H2O(l) M+(aq) + (OH)-(aq) + H2(g) Group 2: M(s) + 2 H2O(l) M+2(aq) + 2 (OH)-(aq) + H2(g,These reactions are very ex 。

5、othermic and increase in violence from the lightest to the heaviest elements in the group (enough to ignite the H2 for the heavier elements). The non-reversible nature of this reaction means that such metals are very useful for drying many kinds of solvents,The s-block metals are used as reducing ag 。

6、ents for an immense number of different types of compounds,More generally,Group 1: M(s) + HOR M+ + (OR)- + H2(g) Group 2: M(s) + 2 HOR M+2 + 2 (OR)- + H2(g,These reactions make metal alkoxides that are very useful for the synthesis of other products using metathesis reactions. Metathesis indicates t 。

7、hat the reagents exchange ligands with one another. Such reactions are especially favourable when it produces a metal halide because of the large exothermicity provided by the lattice or hydration energies,e.g.sMOR + ClPR2 MCl + R2POR MNR2 + ClSiR3 MCl + R3SiNR2,The s-block elements lose their elect 。

8、rons more easily than the other element in the main group so they are usually strong reducing agents and most tend to form ionic compounds. The stabilization that is provided by the crystal lattice (or hydration) energy of the salts they make helps to favour many reactions,One of the stranger conseq 。

9、uences of the low ionization enthalpy is observed when some of the group 1 metals are dissolved in appropriate solvents, such as liquid ammonia,E.g.: Na(s) (dissolved in NH3 (l) Na+(am) + e-(am,Na+(am) + 2 (NH2)-(am) + H2(g,At low concentration this is a blue solution that contains solvated electron 。

10、s! If the reaction warms up or is catalyzed, the free electron reacts with the solvent to reduce some of the protons in the solvent to produce hydrogen gas,This demonstrates the reducing ability of the alkali metals and is a very common and useful property of these elements,X-ray crystal structure o 。

11、f Cs+L2e,Solutions of s-block metals in liquid NH3,group 1 metals and the group 2 metals Ca, Sr and Ba dissolve in liquid NH3 to give metastable solutions,N,H,2,N,a,H,H,2,SODIUM-LIQUID AMMONIA CHEMISTRY,or Fe3,Fe,gas,Royal blue electron solution,Clear sodium amide solution,catalyst required for this 。

12、 step,AMIDE ION,Strong Base,x2,Dilute solutions of alkali metals in liquid NH3 have manyapplications as reducing agents,Reaction with O2,Alkali metals form oxides when they are burnt in air. The nature of the oxides varies among the elements. For example lithium forms monoxide (Li2O), sodium forms p 。

13、eroxide (Na2O2) and the remaining elements mainly form superoxides with very little amounts of peroxides. These reactions are given as below: 4Li + O2 2 Li2O (Lithium monoxide) Na + O2 Na2O2 (Sodium peroxide) K + O2 KO2 (Potassium superoxide,The reason for formation of peroxides and superoxides as w 。

14、e move down the group is due to increased stability of the larger cations through lattice energy. Lithium on the other hand, due to stronger attraction exerted by the nucleus due to smaller size attracts the electrons strongly preventing the reaction with another oxygen atom. Hence, it forms only mo 。

15、noxide but not peroxide or superoxides,Lattice Energies of Alkali Metals Halides (kJ/mol,fH & fG of oxides,Langes,The Crown Ethers,The alkali metals are complexed quite strongly by THF and glymes, but the effect becomes really marked for the so-called crown ethers,Interaction with Crown Ethers,Li+ i 。

16、s most strongly bound in dicylohexyl-14-crown-4 Na+ fits well in benzo-15-crown-5 Rb+ fits best in dicyclohexyl-21-crown-7 Cs+ fits best in dicyclohexyl-24-crown-8 The stability orders differ depending on the method of comparison (calculation, gas-phase, solution etc): experimentally in solution, it 。

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标题：IIA无机化学|无机化学英文课件：05 group IA and IIA