# User:Tazeen/pHmeter

Delhi Universitry Syllabus for B.Sc (P) I year

CH - 104 LABORATORY: CHEMISTRY AND ANALYTICAL TECHNIQUES No of periods per week - 6

Note: 1. Theory needed for understanding of Experiments and the basic principles involved in instrumentation may be discussed in the Lab. 2. The practical examination shall be of 6 hours duration spread over three sessions of two hours each. Practical examination will include three exercises - one each out of the following inorganic, organic and physical chemistry experiments. Different students should be given different exercises as far as possible.

Experimental errors and their statistical treatment Types of errors, precision and accuracy, absolute and relative uncertainty, Gaussian distribution, mean value and standard deviation. Students’ T and Q tests, confidence intervals, central chart spread sheets and finding best straight line. The students must be encouraged to perform these tests wherever possible using computational techniques.

Separation Techniques

1. Chromatography

Separation of mixtures (combination of two ions / compounds to be given)

• Paper chromatographic separation of Fe3+, Al3+ and Cr3+
or

Paper chromatographic separation of Ni2+, Co2+, Mn2+ and Zn2+.

• Identify and separate the components of a given mixture of amino acids (glycine, aspartic acid, glutamic acid and tyrosine) by paper chromatography.
• Separate and identify the sugars present in the given mixture (glucose and fructose) by paper chromatography. Report Rf values.
• Separation of ortho and para-nitroaniline by column chromatography.

Measure the Rf values in each case.

1. Electrophoresis

a)Separation of mixtures of 2 or 3 amino acids viz. Glycine, lysine, aspartic acid/glutamic acid by electrophoresis.

1. DNA Isolation Isolation of DNA from an actively growing tissue by disruption of non-covalent bonds among various macromolecules (cauliflower or onion can be used)

1. Electroanalytical Methods:
• Conductometry (All standard solutions to be provided) (a) Determine the equivalent conductance of a weak electrolyte (acetic acid) at different concentrations.
              Determine the strength of the given HCl solution by titrating it   against NaOH solution conductometrically.



2. pH-metry and Potentiometry

a. (i) Prepare buffers of

CH3COOH and CH3COONa

OR

Citric acid and Na2HPO4 and determine their pH values using glass electrode.

(ii) Determine the pH of given aerated drinks, fruit juices, shampoos and soaps. (use diluted solutions of soaps and shampoos to prevent damage to glass electrodes)

b. Titrate given solution of HCl with NaOH pH-metrically. c. Determine the strength of given solution of K2Cr2O7 by titrating with Mohr’s salt solution potentiometrically.

  Introduction to Spectroscopic Techniques


1. Colorimetry/Spectrophotometry

(a) To plot absorbance vs. wavelength curve for a given coloured compound and identify λmax for it. (b) To draw calibration curve [Absorbance at λmax vs. concentration] for various concentrations of a coloured solution and estimate the concentration of the same in a given solution. 2. Flame Techniques

Flame photometry: Determine the concentration of Na+ and K+ using flame photometry.

Project Work

Students must be encouraged to do projects using the above techniques and also the kits prepared by other Institutes such as Central Pollution Control Boards, Development Alternatives.