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Is o2 2- paramagnetic or diamagnetic
If any of the molecular orbital contains unpaired electrons, it is regarded as paramagnetic. Since O2 has (pi*2Px1=pi*2Py1) config. its paramagnetic while O2²- has (pi*2Px=pi*2Py²) config. it is diamagnetic.
If The Endpoints Of Have The Coordinates A(9, 8) And B(-1, -2), What Is The Midpoint Of ?
EQUILIBRIUM 231SUMMARYWhen the number of molecules leaving the liquid to vapour equals the number ofmolecules returning to the liquid from vapour, equilibrium is said to be attained and isdynamic in nature. Equilibrium can be established for both physical and chemicalprocesses and at this stage rate of forward and reverse reactions are equal. Equilibriumconstant, Kc is expressed as the concentration of products divided by reactants, eachterm raised to the stoichiometric coefficient.For reaction, a A + b B c C +d DKc =
c d/ a bEquilibrium constant has constant value at a fixed temperature and at this stageall the macroscopic properties such as concentration, pressure, etc. become constant.For a gaseous reaction equilibrium constant is expressed as Kp and is written by replacingconcentration terms by partial pressures in Kc expression. The direction of reaction canbe predicted by reaction quotient Qc which is equal to Kc at equilibrium. Le Chatelier’sprinciple states that the change in any factor such as temperature, pressure,concentration, etc. will cause the equilibrium to shift in such a direction so as to reduceor counteract the effect of the change. It can be used to study the effect of variousfactors such as temperature, concentration, pressure, catalyst and inert gases on thedirection of equilibrium and to control the yield of products by controlling these factors.Catalyst does not effect the equilibrium composition of a reaction mixture but increasesthe rate of chemical reaction by making available a new lower energy pathway forconversion of reactants to products and vice-versa.All substances that conduct electricity in aqueous solutions are called electrolytes.Acids, bases and salts are electrolytes and the conduction of electricity by their aqueoussolutions is due to anions and cations produced by the dissociation or ionization ofelectrolytes in aqueous solution. The strong electrolytes are completely dissociated. Inweak electrolytes there is equilibrium between the ions and the unionized electrolytemolecules. According to Arrhenius, acids give hydrogen ions while bases producehydroxyl ions in their aqueous solutions. Brönsted-Lowry on the other hand, definedan acid as a proton donor and a base as a proton acceptor. When a Brönsted-Lowryacid reacts with a base, it produces its conjugate base and a conjugate acid correspondingto the base with which it reacts. Thus a conjugate pair of acid-base differs only by oneproton. Lewis further generalised the definition of an acid as an electron pair acceptorand a base as an electron pair donor. The expressions for ionization (equilibrium)constants of weak acids (Ka) and weak bases (Kb) are developed using Arrhenius definition.The degree of ionization and its dependence on concentration and common ion arediscussed. The pH scale (pH = -log ) for the hydrogen ion concentration (activity) hasbeen introduced and extended to other quantities (pOH = – log ) ; pKa = –log ;pKb = –log ; and pKw = –log etc.). The ionization of water has been considered andwe note that the equation: pH + pOH = pKw is always satisfied. The salts of strong acidand weak base, weak acid and strong base, and weak acid and weak base undergohydrolysis in aqueous solution.The definition of buffer solutions, and their importanceare discussed briefly. The solubility equilibrium of sparingly soluble salts is discussedand the equilibrium constant is introduced as solubility product constant (Ksp). Itsrelationship with solubility of the salt is established. The conditions of precipitation ofthe salt from their solutions or their dissolution in water are worked out. The role ofcommon ion and the solubility of sparingly soluble salts is also discussed.2020-21