Laboratory Course I

Basic techniques involved in synthetic organic chemistry
i.    Different types of glass wares
ii.    Filtration
iii.    Distillation (distillation at atmospheric pressure, steam distillation, fractional distillation and distillation at reduced pressure).
iv.    Recrystallization and melting point correction.
v.    Use of decolourising carbon.
vi.    Thin layer chromatography.
 

Synthesis (Green methods)

1. One step synthesis (any four)

1. Halogen Addition to C=C bond (Bromination of Trans stilbene)
2. Aldol condensation (Synthesis of dibenzal propanone)
3. Acetylation (synthesis of acetanilide from aniline)
4. [4+2] cycloaddition Reaction ( Diel’s Alder reaction between furan and maleic acid )
5. Pechmann Condensation for Coumarin synthesis (Clay catalysed solid state synthesis of 7-hydroxy -4-methyl coumarin)
6. Solvent free reaction (microwave assisted ammonium formate medicated Knoevenagel reaction)

2. Two step synthesis

1. Benzoin → benzil → benzilic acid
2. Benzophenone → benzopinacol → benzapinacolone
3. Acetanilide → p-bromoacetanilide → p-bromoaniline
4. Preparation of ionic liquid (1-pentyl-3-methylimidazolium bromide) and its application towards synthesis of 2-phenyl-benzothiazole.

Synthesis ( Conventional  methods)

Two step synthesis (any two)

i) Acetanilide → p-nitroacetanilide → p-nitroaniline

ii) o-hydroxyacetophenone → o-benzyloxyacetophenone → o-hydroxy dibenzylmethane

iii) Benzophenone → benzophenone oxime → benzanilide

iv) Resorcinol → flouroscein → Eosin
Extraction of organic compounds from natural resources (any three)
i.    Isolation of caffeine from tea leaves
ii.    Isolation of casein from milk
iii.    Isolation of lactose from milk
iv.    Isolation of nicotine dipicrate from tobacco
 

A list of experiments under different heading is given below. Students are required to perform 8-10 experiments.
 
 

Adsorption (Any two)

1. To study the absorption of acetic acid or oxalic acid from aqueous solution by activated charcoal or animal charcoal and examine the validity of Freundlich and Langmuirs adsorption isotherms.
2. To compare cleansing power of samples of two detergents.
3. Study the variation of surface tension of solution of n-propyl alcohol with concentration and hence determine the limiting cross section area of alcohol molecule.
4. To determine the radius of molecule by viscosity measurements (e.g.Glycerol)

Thermochemistry

1. Determine the solubility of benzoic acid at two temperature in water-DMSO mixture (4:1)  and calculate the enthalpy change of the dissolution process.
2. Determine the lattice energy of calcium chloride from its heat of solution using Born-Haber cycle. You are provided the Enthalpy changes for Ca⁺² (g) → Ca(g) 2Cl^- (g) → 2Cl (g), Ca (g) → Ca (s), 2Cl (g) → Cl₂ (g) and Ca (s) + Cl (g) → CaCl₂ (s) as -451.1, 174.3, -38.8, -58.0 and -190.0 Kcal/mole respectively.

Chemical Kinetics (any three)

1. Determine the relative strength of two acids (hydrochloric acid and sulphuric acid) by studying the hydrolysis of an ester (methyl acetate or ethyl acetate) at the room temperature).
2. Determine the rate constant of the hydrolysis of an ester such as methyl acetate catalyzed by an acid (0.5N HCl or 0.5N H₂SO₄) and determine the energy of activation.
3. Study the kinetics of the reaction between K₂S₂O₈ (potassium persulphate) and KI (potassium iodide) and determine the rate constant and the energy of activation of the reaction.
4. Study the kinetics of saponification of ethyl acetate by sodium hydroxide and determine the rate constant.

Polarimeter

i.          Determine the rate constant of the inversion of cane sugar in presence of hydrochloric acid and sulphuric acid by using polarimeter and evaluate the relative strength of the two acids.

pH Metry (Any three)

1. Titrate the given mixture of CO₃^-2 and HCO₃^- ions against a strong acid, 0.1N HCl solution and determine their strength.
2. Titrate a tribasic acid (H₃PO₄) against a strong base (NaOH).
3. Determine the dissociation constant of a weak acid.
4. To determine the acidic and basic dissociation constant of an amino acid and hence its isoelectric point.
5. Determination of pK values of maleic / malonic acid by potentiometric titration with NaOH using glass electrode.

Electrochemistry       

1. Estimate the amount of halide ions present in a given solution by titration with silver nitrate conductometrically.
2. Determine the solubility and solubility product of a sparingly soluble salt like BaSO₄, or PbSO₄ or AgCl in water conductometrically.