Physical Chemistry Lab I

A list of experiments under different heading is given below. Students are required to perform 10-12 experiments (minimum two from each category).

Concentration of solutions, expressing concentration in physical units and chemical units, unit conversion, preparation of solutions, primary and secondary standards.

Knowledge of basic terms regarding phase equilibrium, thermochemistry, optical measurements, conductance, chemical kinetics, adsorption, pH and surface tension.

Introduction to instrument - pH meter, conductivity meter, spectrophotometer and thermostat.

Thermochemistry

1. To determine the solubility of benzoic acid at two temperatures in water-DMSO mixture (4:1)  and to calculate the enthalpy change of the dissolution process.
2. To determine the lattice energy of calcium chloride from its heat of solution using Born-Haber cycle. 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) + 2Cl (g) → CaCl₂ (s) as -451.1, 174.3, -38.8, -58.0 and -190.0 Kcal/mole respectively.
3. To determine the partial molal volume of solute (KCl or NaCl) and solvent in a binary mixture at normal temperature and pressure.
4. To determine the partial molar volume of methanol/ethanol-water system at normal temperature and pressure.

Phase Equilibrium

1. To determine the solubility diagram for a three component liquid system chloroform, acetic acid and water / toluene, acetic acid and water / benzene ethanol and water. To discuss the diagram in a light of phase, component and degree of freedom.
2. Nernst Distribution Law: To determine the formula of a complex ion formed between cupric ion and ammonia by distribution method.
3. To  study the freezing point curve of two component simple eutectic system (acetamide- benzoic acid/nahthalene-benzoic acid)

Polarimeter

1. To 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

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

Spectrophotometry

1. To determine the acid dissociation constant (pKa value) of methyl red.
2. To determine the stability constant and composition of FeSCN⁺² complex/ Fe(III)-salicylic acid/iron-phenanthroline complex/ zirconium alizarin red-S complex by jobs method of continuous variation and mole ratio method.