Analytical Techniques in Chemistry — DU B.Sc. (Prog.) Applied Life Sciences with Agrochemicals and Pest Management pertaining to Chemistry Previous Year Question Papers

Analytical Techniques in Chemistry - DSC B.Sc. (Prog) AGROCHENICAL AND PHST 1. The differenee between the tn:ie value and measured value with regard to sign,rm is the ........ ro ....... error li 2. The anfflog. of i.946 sfaould contain ....... ` ..... Significant figures. 3~. The number Of sigrifieant figures -in the valrie 6.023 X 10 23 is ............ 4. Tfie square if the standard deviation is known as .............. 5. The Principle' of solvent extraction is governed by ............... law. 6. For identification purpose in chromatograpky the spots are characterized by their factors. 7. In conductometry ,............. is the unit Of measurement for electrical conductivdy. 8. Radiation source used in UV-Visible spectrophotometer is .................. 9.. The unit of molar extinction co`refficient is ................ 10.The various types of bending vibrations are ............. 3 ,..............., 11. The fingerprint region in IR spectra ranges from.... 12. The value of TMS protons (in NMR) in & scale is …............ 13. A quartet has an intensity ratio of signal is.... 14. Shielding shift the signa........... while the deshielding shifts the signal. .... 15. Mass spectrum is a record of the relative abundance versus.. Q2 (a) Discuss the various absorption laws involved in UV-visible Spectroscopy. Derive Lambert-Beers law. What are the limitations of Lambert-Beers law? (b) What are the advantages of TMS used as internal standard in NMR Spectroscopy? Calculate the chemical shift for proton signal appearing at 120 Hz relative to TMS at given oscillator frequency of 60 MHz. (c) Sketch the 'H NMR spectrum for each the following compounds with Peak intensities (iii) CH3-OCH,-CH3 (iv) Benzaldehyde 03(a) Explain the isotopic effect in mass spectrometry. Determine possible Isotopic Combinations when two chlorine atoms combine to form Cla and also calculate the relative peak intensities. (b) What is the effect of hybridisation of carbon on the stretching frequency of C-H bond? What are the factors which can influence the position of IR absorption bands from the normal position? Arrange the following according their vibrational frequency: (c) What are the selection rules of Infra-red spectroscopy? Calculate the wave number of stretching vibrations of a carbon-carbon double bond. Given: force constant (k= 10 x 105 dynes cm-1). (5,5,5) (a) What is meant by term chemical shit? What are the Factors affecting chemical shift? (b) How would you distinguish Bathochromic shift and hypsochromic shift? (c) Write the various selection rules involved in UV-visible spectroscopy. (d) 2.5 x 10-4 M solution of a substance in a 1 cm length cell at Amax 245 nm has absorbance 1.17. Calculate Emax Or molar extinction coefficient for this transition. Q5 (a) Draw and explain the conductometric titration curve of the following (i) Strong Acid vs Strong Base (ii) Weak Acid vs Strong Base (iii)Mixture of Strong Acid & Weak Acid vs Strong Base