Simplified Chemistry

A method of calculating atomic and molecular structure directly from the first principles of quantum mechanics, without using quantities derived from experiment (such as ionization energies found by spectroscopy) as parameters. Ab-initio calculations require a large amount of numerical computation; the amount of computing time required increases rapidly as the size of the atom or molecule increases. The development of computing …

Solubility product: The product of concentrations of ions in saturated solution of an electrolyte at a given tempera­ture is constant and is known as solubility product. For silver chloride, the equilibrium is formulated as follows. Undissolved salt ⇋ ions in solution AgCl(s) = Ag+(aq)+ Cl (aq) K = [Ag+][Cl–]/[AgCl] The concentration of the undissolved salt is constant (say k) at …

Le-Chatelier principle: if an equilibrium system is subjected to a change, reaction will occur in such a way as to counter act the imposed change. Example. Manufacture of Ammonia:  N3 (g) + H2(g) → 2NH3(g) ; ΔH = -93.6kJ. (i) Effect of pressure: The increases in pressure causes the-equilibrium to shift from left to right. Therefore forward reaction is favored. …

Internal energy: The energy stored in a fixed amount of a substance (atom or molecule) is known as its internal energy. It is denoted by the sign E. Change in internal energy: It is the difference in the internal energies of the product and the reactant species taking part in a chemical reaction at constant volume. It is denoted by …

Hybridization :  is a mathematical concept which implies for the mixing of various atomic orbitals with slightly different energies of the same atom to construct equal number of hybrid (mixed) orbitals of equal energy, in a molecule. For an isolated atom, however. the hybridization has no meaning. Hybridization involves promotion of electron from a lower energy state to a higher …

Hydrogen bond: It is a bond formed between a hydrogen atom attached to a highly electrovalent atom (F,O,N) and another highly electronegative atom of the same or different molecule and having a lone pair of electrons. Condition for hydrogen bonding : (i) The electronegative atom attached to the hydrogen should be small. (ii) The electronegativity of the atoms to which …

Difference between σ and π bonds σ bond π bond (i) The orbitals overlap along their axes. (ii) The overlap is quite appreciable and the bond formed is a strong bond. (iii) s-orbitals can parti­cipate in the bond formation. (iv) In case of p-orbitals, the participating lobe is stretc­hed and the  size of the other lobe is reduced. (v) The …

Chemical bond: The attractive force which holds together the constituent atoms of chemical compounds is called chemical bond. Combination of atoms: It. is universal law of nature that systems with lower energy are more stable. So atoms combine to form a molecule because it has a· lower energy i.e., more stable. Modern concept of chemical bonding: The formation -of a …

According to Newton’s corpuscular theory, light is propagated as a stream of particles, called corpuscules. This could justify the phenomenon of reflection and refraction of light but failed to explain the phenomenon of diffraction, interference etc. Clerk Maxwell suggested that light waves are associated with both electric and magnetic fields i.e., light may be described as electromagnetic waves or radiations. …

Chemical nomenclature is the system of names that chemists use to identify compounds precisely. The systematic method of naming compounds is vital to the study of chemistry, because when a new substance is formulated, it must be named in order to distinguish it from all other substances. Using this systematic method of naming compounds, the positive part is named and …