UPSC Chemistry 2023

(a) (i) Find the wavelength of the emitted light when 1.0×10⁻²⁷ g particle in a one-dimensional box of length 3 Å goes from nₓ = 2 to nₓ = 1 level. (ii) Explain the Heisenberg unc…

(a) Using the Gibbs equation for a closed system in the absence of non-expansion work at constant composition, answer the following : (i) Deduce the thermodynamic relations for th…

(a) Determine the electronic and molecular geometry of [BrF₅] and [ICl₂]⁻ interhalogen compounds. 10 (b) Answer the following questions based on the phase diagram given below : (i…

(a) The volume of a certain gas is found to be 5.0×10⁻⁴ m³ mol⁻¹ at 273 K and 3.0×10⁶ Pa. This gas obeys the van der Waals' equation with a = 0.50 m⁶ Pa mol⁻². (i) Calculate the o…

The decomposition of AB₂ to AB and B is a first-order reaction with k = 2·8 × 10⁻⁷ s⁻¹ at T = 1000 K. The atomic weights of A and B are 12 and 32, respectively. (i) Find the half-…

Complete the following reactions and draw the structure of the major product(s) formed: (i) 2XeF₆ + SiO₂ → ____ 50 °C (ii) NH₄NO₃ → ____ + ____ 520 K (iii) N₂O + NaNH₂ → ____ 470…

(a) Explain the common structural features of two major iron-containing proteins—haemoglobin and cytochrome c present in the human body. Explain the coordination chemistry involve…

(a) Sketch the synthesis of [Fe(η⁵-C₅H₅)(η⁵-C₅H₄COCH₃)] and [Fe(η⁵-C₅H₅)(η⁵-C₅H₄COOH)] complexes starting from [Fe(η⁵-C₅H₅)₂]. (10 marks) (b) Calculate the spin only magnetic mome…

1.(a)(i) pKₐ value of cyclopentadiene is almost similar to water. Explain. 5 marks 1.(a)(ii) Rate of hydrogen exchange reaction in the above compound (A) is 6000 times faster than…

2.(a)(i) Based on Hückel rule, predict the above compounds as aromatic, antiaromatic, and nonaromatic. 5 marks 2.(a)(ii) Identify the above reactions that show primary kinetic iso…

3.(a) Would you expect the above conversion to require heat or light? Explain using molecular orbital diagram. (15 marks) 3.(b) 3-Phenyl-4-pentenal is synthesised in the following…

4.(a)(i) Complete the above reaction and write the steps involved in the reaction. (5 marks) 4.(a)(ii) Arrange the above alkenes in ascending order of their relative rate of bromi…

(a) How many signals would you expect in the ¹H NMR spectrum of above compounds ? Mark these protons. 10 marks (b) Compare the C=C stretching vibrations in the above compounds and…

(a)(i) The frequencies of vibration of the following molecules in their v = 0 states are HCl : 2885 cm⁻¹; D₂ : 2990 cm⁻¹; DCl : 1990 cm⁻¹ and HD : 3627 cm⁻¹. Calculate the energy…

(a) (i) Draw the structure of 2'-deoxycytidine-3'-monophosphate. (ii) Why nucleotides and nucleic acids are acidic ? Mention the factor(s) that stabilize the DNA duplex. (iii) Sho…

(a)(i) For the following compound : (i) Identify the site of initial ionization under EI conditions. (ii) Draw the structure of ion having m/z = 58 value. (iii) Calculate the m/z…