Chemistry World

Photoelectric effect:         Photon:                  in 1905 Einstein suggest that light(electromagnetic radiations) is made up of tiny particles known as photon . photons are the packets of energy . Einstein suggested that energy is not emitted continuously but is emitted as individual amount of energy known as Quantum energy. Energy of Photon: The energy of photon is given by Einstein                                      E=hv where,                E= energy of photon                h=plank's constant                v=frequency Properties of Photon: Photon have no mass. Photon posses no charge and are not deflected by electric or magnetic field. The values of all quantum number is zero for Photon. In empty space they move with the speed of light. when radiations interact with matter it act as photon. energy and momentum relation is given by    E=pc Photon are virtual particles  their energy is directly proportional to frequency and inversely

Isomerism The phenomena in which compounds have same molecular formula but different structural formula is called isomerism. e.g propadiene propyne Structural Isomers  having different structural formulas because their atoms are joined together in different number of ways. It is formed: arrangement of Carbon skeleton e.g. The formula of C4H10 gives two possible structure, butane and methylpropane: butane methyl propane   Position isomerism e.g. propan-1-ol and propan-2-ol  Functional Isomerism e.g. the molecular formula C2H60 represents both ethanol and methoxymethane.  Ring chain isomerism Cyclic alkanes are isomeric with alkenes, e.g. cyclopropane and propene

As in any field of study, careful attention to nomenclature is required. The rules for names and formulas of coordination compounds are given here, with examples to show their use, but we need to be aware of changes in nomenclature with time. In many cases, the notation used by those who first prepared a compound is retained and expanded; in other cases, conflicting rules for names are proposed by different people and only after some time is a standard established. The literature naturally includes papers using all the possible names, and sometimes careful research is necessary to interpret those names that had relatively short lifetimes. Following are the major rules required to name the compounds in this text and those found in the general literature. Reference to more complete sources may be needed to determine the names of other compounds.12 Organic (and some inorganic) ligands are frequently named with older trivial names rather than with IUPAC (Internatio

An Overview of coordination chemistry Historically, inorganic chemistry is the oldest branch of chemistry. Classical inorganic chemistry was primarily concerned with the preparation and studies of the properties of all the elements and their compounds, including the simple compounds of carbon. It is very difficult to determine the exact date of preparation of the first coordination compound. The chemistry of complexes may be said to have originated in 1704 with the discovery of Prussian blue by Diesbach, a colour maker. After this one might site the investigation of the products of oxidation of ammonical cobalt solution of Tassaert (1799). In the years that followed, Cleve, Wolcott Gibbs, Blomstrand and Fermy did a large amount of effort towards the study of complexes. By 1870, a great deal of information on the complexes had been gathered and it was Prof.Jorgenson who for the first time methodized much of this field by the preparation and characterization of a large number of comp

Definition of d-block elements The elements of periodic table belonging  to group 3 to 12 are known as d-Block  elements . because in these elements last  electron enters in d sub shell or d orbital  The d -block elements lies in between s- and  p-block elements in the long form of  periodic table. Electronic Configuration •          Across the 1 st row of the d block (Sc to Zn) each element –         has 1 more electron and 1 more proton –         Each “additional” electron enters the 3d sub-shell –         The core configuration for all the period 4 transition elements is that of Ar •          1s 2 2s 2 2p 6 3s 2 3p 6 Energy level of Argon Energy level of Transition metals Chromium and Copper •            Cr and Cu don’t fit the pattern of building up the 3d sub-shell, why? –         In the ground state electrons are always arranged to give lowest total energy –         Electrons are negatively charged and repel each othe

Physical properties of d-block elements Key points: The properties of the d metals are largely derived from their electronic structure, with the strength of metallic bonding peaking at Group 6; the lanthanide contraction is responsible for some of the anomalous behaviour of the metals in the 5d series. The d block of the periodic table contains the metals most important to modern society. It contains the immensely strong and light titanium, the major components of most steels ( Fe, Cr, Mn, Mo ), the highly electrically conducting copper, the malleable gold and platinum , and the very dense osmium and iridium . To a large extent these properties derive from the nature of the metallic bonding that binds the atoms together. Generally speaking, the same band structure is present for all the d-block metals and arises from the overlap of the (n 1)s orbitals to give an s band and of the nd orbitals to give a d band. The principal differences between the metals is