Some Basic Concepts of Chemistry

Basic Concepts of ChemistryMole FactsMole-related FormlaeEmpiricalFormula vsMolecularFormulaNumber ofentities/Avogadro'snumber = Moles(n) = Mass of substance/Molar MassMole Concept in SolutionsNo. of entities = MolesX Avogadro's NumberMolar Mass (M) = Sumof the atomic masses of the elements present in a molecule.Avogadro's No.(NA) = 6.022×1023 Definition:No. of atoms/molecules present in one moleof an element/compound.Atomic mass (A) = Mass of 1 mole of atomMole of atoms/molecules/ions/electrons = (No. of atoms/molecules/ions/electrons)/Avogadro's No.PercentageComposition (mass %)= No. of parts by massof the element or contituents/ Molecularmass of the compound x 100Mass percent (%) = (mass/given mass of solute)/mass of givensolution x 100Mole fraction (x) = No.of moles of the component/total no. of moles of the componentMole fraction of the solute = (Xa) - nA/nA+nB Molarity (M) = No. of the moles of the solute(n)/Volume of the solution in litres (V), where n-w(given mass) /(molar mass)If the solution of molarity M1 & volumeV1 is diluted to volumeV2 and its new molarity M2, no. of moles of the solutedoes not change. Hence, M1V1 = M2V2 Molality (m) - no.ofmoles of the solute(n)/mass of solvent inkg, where n-w(given mass)/(molar mass)Parts per million(ppm) = mass of thecomponent/mass of solution x 106Molecular Formula =n x Empirical FormulaMass/Volume = Density1 Mole =Atomic/Molecularweight of element/compound(in grams)1 Mole of atoms1 Mole of Molecules Gram AtomicMass 6.022×1023GramMolecularMass22.4L at S.T.P. 6.02×1023Molecules
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