Beryllium does not react with water and how hydration enthalpy of beryllium is more and how it is possible?
Answers
Explanation:
Introduction
Beryllium having the electronic configuration 1s22s2 almost exclusively forms covalent compounds due to its high ionisation potentials and the small size and therefore high polarising power of the dipositive cation. Compounds of beryllium have covalencies of two, three or four for the metal atom. There are no known compounds with a coordination number greater than four, since the atomic orbitals of principal quantum number three are of too high an energy to participate in bond formation. The coordination number of two arises from the use of sp hybrid orbitals by beryllium to give a linear molecule as found for Bu2tBe1 while the rather unusual coordination number of three is found, for example, in Me2BeNMe3,2 in which the metal must make use of sp2 hybrid orbitals. Beryllium however, has a strong tendency to form tetravalent compounds using sp3 hybrid orbitals to give tetrahedral bonding. The chemistry of organoberyllium compounds is intermediate between that of magnesium and the subgroup; zinc, cadmium and mercury. The covalent radius of magnesium (140 pm) is somewhat larger than that of beryllium (93 pm) and therefore allows a greater volume of ligand to be bonded to the metal, so that magnesium compounds tend to be more associated than beryllium compounds and have higher coordination numbers. As beryllium is less electropositive than magnesium, the BeC bond is less polar than the MgC bond and so beryllium alkyls are less reactive than their magnesium counterparts. Nevertheless, the BeC bond is still very polar and this is largely responsible for its reactivity, for example in its reactions with protic acids, except when steric obstruction of the attacking reagent prevents reaction, as is the case with (PhBeOCPh3)2 which dissolves in neither sulphuric (1 mol dm−3) nor nitric (6 mol dm−3) acids at room temperature.3
The high toxicity of beryllium compounds,4–6 together with the air sensitive nature of organometallic derivatives, have limited study in this promising area of chemistry. Much of the experimental development of an understanding of this area is due to work by Coates and co-workers between 1964 and 1974 at Durham and Wyoming. Since 1974, publications on experimental work have diminished considerably and there has been a much greater emphasis on molecular orbital studies, so that there are now many theoretical studies of both real and fanciful organoberyllium systems.7–33 Review articles particularly recommended are those by Coates and Morgan34 and by Fetter.35 Two books36,37 contain sections devoted to organoberyllium chemistry, and two Russian38,39 and one French reviews40 have also appeared as well as a review devoted to organoberyllium–nitrogen and –oxygen systems41 and another to the alkyl derivatives of the Group II metals.42 A survey of structural aspects of electron-deficient organometallic compounds of Li, Be, Mg and Al has been published recently.43
As the cyclopentadienyl compounds of beryllium are somewhat different from other organoberyllium compounds, these are discussed in this chapter as a separate section.
Answer:
beryllium does not react with water
Explanation:
because beryllium has coating of beryllium oxide BeO