UPSC Chemistry 2024

(a) (i) Determine the distance from the nucleus at which the electron is most expected in the hydrogen atom in its ground state. [Given : The normalized radial function for hydrog…

(a) State Heisenberg's uncertainty principle. Show that for a particle in a one-dimensional box having length from 0 to L, the two normalised eigen functions corresponding to the…

(a) (i) Calculate the coefficient of viscosity of air at temperatures : (I) 298 K and (II) 0 K. Assume that the collision cross-section (πσ²) of air is 0·28 (nm)² and average mola…

(a) A new drug has been synthesized and its phase diagram is explored. It is found that near its triple point, vapour pressure over the liquid (Pl) and over the solid (Ps) are giv…

(a) Indicating 'Fluorescence' and 'Phosphorescence' processes in Jablonski diagram, distinguish between both processes. (10 marks) (b) (i) How does water condense onto glass? (5 m…

(a) (i) Calculate the number of moles of HCl (g) produced by the absorption of one Joule of radiant energy of wavelength 480 nm in the reaction H₂ (g) + Cl₂ (g) → 2HCl (g) if the…

(a) Show the splitting of 'd' orbitals in square planar field according to Crystal Field Theory (CFT). Comment on the following statement : 'The difference in energy between the d…

(a) 'All the F atoms appear indistinguishable in the ¹⁹F NMR spectrum of sp³d hybridized PF₅ molecule.' Explain how. (10 marks) (b) (i) Draw all the possible structural dispositio…

(a) (i) Classify the following as aromatic, nonaromatic or antiaromatic : (1) Azulene (2) Pyridine (3) Sydnone (4) Cyclooctatetraene (5) Cyclopentadienyl cation (5 marks) (ii) Tho…

(a) (i) Consider the following reactions : EtO⁻ with substrate (Rate = k_H) and EtO⁻ with deuterated substrate (Rate = k_D). It was observed that k_H/k_D = 7.1. Based on this data…

(a) (i) Predict the reaction mechanism and the major product formed when methyl cyanide is heated with dilute hydrochloric acid. (10 marks) (ii) Addition of bromine to cis-2-buten…

(a) (i) Consider the following reaction : Name the product X and outline the mechanism indicating the rate-determining step. (10 marks) (ii) Indicate the major products of the fol…

(a) Write the structures of the bases present in DNA and RNA. Compare the stability of DNA and RNA. (10 marks) (b) Predict the structure of P, Q and R in the following sequence of…

(a) (i) Explain the various steps involved in benzoyl peroxide-initiated polymerization of ethylene to give polyethylene. (10 marks) (ii) Predict the physical properties of atacti…

(a) Calculate the value of λ_max in the following compounds using Woodward-Fieser rules : [structures A, B, C] (15 marks) (b) Predict the structure of X, Y and Z in the following…

(a) Ethanolic solution of compound I on irradiation leads to the formation of compounds II, III and IV. The resulting reaction mixture exhibits bands at 1787, 1740, 1715 and 1685…