These MP Board Class 11th Chemistry Notes for Chapter 12 Organic Chemistry: Some Basic Principles and Techniques help students to get a brief overview of all the concepts.

MP Board Class 11th Chemistry Notes Chapter 12 Organic Chemistry: Some Basic Principles and Techniques

→ Isomerism : Two or more compounds which are different in their properties but have same molecular formula, are called isomers and this phenomenon is called isomerism.

→  Types:

  1. Chain isomerism : When difference exists in chain of carbon atoms.
  2. Position isomerism : When functional group is attached in different positions in same chain.
  3. Functional isomerism : When functional groups are different.
  4. Metamerism : Functional group is same but alkyl groups attached with it are different.
  5. Tautomerism : Special type of functional group isomerism in which both the isomers of a compound are in dynamic equilibrium.
  6. Ring chain isomerism : Structure of compound is open chain or cyclic.
  7. Optical: Formation of enantiomers of different optical properties by chiral molecules, (viii) Geometrical: Formation of cis-trans isomers due to restricted rotation in compounds of C = C double bond.
  8. Conformation : Formation of various spatial arrangements due to free rotation around C—C single bond.

MP Board Class 11th Chemistry Notes Chapter 12 Organic Chemistry: Some Basic Principles and Techniques

→ Alkane : Saturated hydrocarbon, paraffin (less reactive) general formula C„H2)1+2, regular tetrahedral structure, H—C—H bond angle 109°28′ and sp3 hybridization in C-atom.

→ Conformation in ethane : Two forms (i) Eclipsed : In which H-atoms attached to both carbon are in front of each other.
(ii) Staggered : In which H-atoms of both carbon are in between each other. Low energy and more stable.

→ Conformation of cyclohexane: Two forms (i) Chair or staggered and (ii) Boat or eclipsed.

→ Chirality : Such compounds whose mirror images are non-superimposed.

→ Asymmetric carbon atom : Such a carbon atom to which four different groups are linked.

→ Optical isomers: Compounds which rotate the plane polarized to opposite direction and are mirror image of each other.

→ d – or (+) form : Which rotates the plane polarized light to the right.
Organic compounds of carbon : Compounds of carbon and hydrogen or their derivatives which have carbon-carbon bond.

MP Board Class 11th Chemistry Notes Chapter 12 Organic Chemistry: Some Basic Principles and Techniques

→ Alkyl radicals : Part of molecule after ignoring one hydrogen atom in paraffin hydrocarbon.

→ Functional group : Atom or group of atoms determining the general chemical properties of the organic compound.

→ Homologous series : Series of compounds having common functional group and composed by the difference of —CH2

→ Nomenclature of organic compounds : IUPAC system.

→ l-(or) (-) form : Which rotates the plane polarised light to the left.

→ Racemic mixture : Equimolar proportion of d- and l-form is optically inactive.

→ Inductive effect is pennanent displacement of electrons along the chain of C-atoms.

→ Electromeric effect is temporary effect and occurs at the requirement of attacking species.

→ Resonance effect results in generation of centres of high and low electron density in a mol-ecule.

→ Free radical: Obtained by heterolytic cleavage. No charge but contain unpaired electron.

→ Carbocation : Positively charged carbon atom or group.

→ Carbanion : When negative charge is on carbon atom.

MP Board Class 11th Chemistry Notes Chapter 12 Organic Chemistry: Some Basic Principles and Techniques

→ Meso form : Molecule with one or more chiral centre which is optically inactive due to internal arrangement.

→ Alkene : Carbon atoms of double bond is sp2 hybridized. One cr and 7t-bond is in between carbon. These can show chain, position and geometrical isomerism. General formula CnH2n

→ Alkyne : Carbon atoms of triple bonds are sp hybridized and are linear molecules with bond angle 180°. General formula CnH2n-2. These show chain and position isomerism.

→ Arene : Aromatic hydrocarbons which contain benzene ring. Each carbon atom in benzene is sp2 hybridized in which each bond angle is 120°.

→ Isomerism in Arenes : They have position isomerism. Disubstituted benzene occur in three isomeric forms (ortho, meta and para).

→ Crystallisation:
(a) Simple crystallisation : When hot saturated solution of any substance in a suitable sol-vent is cooled slowly, solid crystalline pure substance is obtained.
(b) Fractional crystallisation : Substances of different solubilities crystallise one by one from the solution which contains two or more than two substances as solute. Substance with least solubility crystallise first.

→ Sublimation : On heating, solid substance directly changes into gaseous state without chang-ing into liquid state and vice-versa.

→ Distillation : The process in which a liquid changes into vapour state and again it condenses back to liquid state. ’

→ Fractional distillation : Mixture of liquids which differ sufficiently in their melting points distil at different temperature. The liquid with low melting point distil first.

MP Board Class 11th Chemistry Notes Chapter 12 Organic Chemistry: Some Basic Principles and Techniques

→ Steam distillation : Liquids having boiling point less than 100°C and immiscible with water, distil with steam. When condensed, different layers can be separated by separating funnel.