2024 Chemistry Past Paper PDF

# CHEMISTRY (55) ## General Instructions : The question paper is divided into four sections. **(1)** **Section A:** * Q. No. 1 contains Ten multiple choice type of questions carrying One mark each. * Q. No. 2 contains Eight very short answer type of questions carrying One mark each. **(2)** **Sec...

# CHEMISTRY (55) ## General Instructions : The question paper is divided into four sections. **(1)** **Section A:** * Q. No. 1 contains Ten multiple choice type of questions carrying One mark each. * Q. No. 2 contains Eight very short answer type of questions carrying One mark each. **(2)** **Section B:** * Q. No. 3 to Q. No. 14 are Twelve short answer type of questions carrying Two marks each. (Attempt any Eight) **(3)** **Section C:** * Q. No. 15 to Q. No. 26 are Twelve short answer type of questions carrying Three marks each. (Attempt any Eight) **(4)** **Section D:** * Q. No. 27 to Q. No. 31 are Five long answer type questions carrying Four marks each. (Attempt any Three) **(5)** Use of log table is allowed. Use of calculator is not allowed. **(6)** Figures to the right indicate full marks. **(7)** For each multiple choice type of question, it is mandatory to write the correct answer along with its alphabet e.g. (a). /(b) /(c) /(d)...........etc. No mark(s) shall be given, if ONLY the correct answer or the alphabet of the correct answer is written. Only the first attempt will be considered for evaluation. **Given:** * R = 8.314 J.K-1, mol-1 * NA = 6.022 × 1023 * F = 96500C ## SECTION -A **Q. 1.** Select and write the correct answer for the following multiple choice type of questions : **(i)** The relation between radius of sphere and edge length in body centered cubic lattice is given by formula: *(a) √3r = 4a* *(b) r = √2x4* *(c) r = √3/4 a* *(d) r = √2/4 xa* **(ii)** The pH of weak monoacidic base is 11.2, its OH- ion concentration is : *(a) 1.585 x 10-3 mol dm-3* *(b) 3.010 × 10-11 mol dm-3* *(c) 3.010 × 10-3 mol dm-3* *(d) 1.585 × 10-11 mol dm-3* **(iii)** Which of the following correctly represents integrated rate law equation for a first order reaction in gas phase : *(a) k = 2.303 x log10 (Pi - P)/2Pi* *(b) k = 2.303 x log10 Pi / (2Pi - P)* *(c) k = 2.303 x log10 Pi / (Pi - P)* *(d) k = 2.303 x log10 (2Pi - P) / (Pi - P)* **(iv)** The spin only magnetic moment of Mn2+ ion is *(a) 4.901 BM* *(b) 5.916 BM* *(c) 3.873 BM* *(d) 2.846 BM* **(v)** The correct formula of a complex having IUPAC name Tetraamminedibromoplatinum (IV) bromide is *(a) [Pt Br (NH3)4] Br₂* *(b) [Pt Br₂ (NH3) 4 ] Br* *(c) [Pt Br₂ (NH3) 4 ] Br₂* *(d) [Pt Br (NH3) 4 ] Br* **(vi)** The allylic halide, among the following is *(a) R-CHR* *(b) CH2=CH-X* *(c) X* *(d) CH2=CH-CH2-X* **(vii)** The product of following reaction is CH3-CH=CH-CH2-CHO OLIAIHA ii) H3O+ ? *(a) CH3-CH2-CH2-CH2-CH2-OH* *(b) CH3-CH=CH-CH2-CH2-OH* *(c) CH3-CH2-CH2-CH2-COOH* *(d) CH3-CH=CH-CH2-COOH* **(viii)** Ozonolysis of 2, 3 dimethyl but-2-ene, followed by decomposition by Zn dust and water gives *(a) acetaldehyde* *(b) propionaldehyde and acetone* *(c) acetone* *(d) acetaldehyde and butyraldehyde* **(ix)** The glycosidic linkage present in maltose is *(a) α,β-1,2-glycosidic linkage* *(b) α-1,4-glycosidic linkage* *(c) β-1,4-glycosidic linkage* *(d) α-1,6-glycosidic linkage* **(x)** The monomer of natural rubber is *(a) Isoprene* *(b) Acrylonitrile* *(c) ε-Caprolactam* *(d) Tetrafluoroethylene* **Q. 2.** Answer the following questions: **(i)** Write the name of the technique used to know geometry of nanoparticles. **(ii)** Write the name of the product formed by the action of LiAlH4/ether on acetamide. **(iii)** Write the structure of the product formed when chlorobenzene is treated with sodium metal in the presence of dry ether. **(iv)** Write the chemical composition of cryolite. **(v)** Write the name of platinum complex used in the treatment of cancer. **(vi)** Write the SI unit of cryoscopic constant. **(vii)** Write the correct condition for spontaneity in terms of Gibbs energy. **(viii)** Calculate molar conductivity for 0.5 M BaCl2 if its conductivity at 298K is 0.01 2-¹cm-1. ## SECTION-B Attempt any EIGHT of the following questions: **Q. 3.** Distinguish between lanthanides and actinides. **Q. 4.** Calculate the mole fraction of solute, if the vapour pressure of pure benzene at certain temperature is 640 mmHg and vapour pressure of solution of a solute in benzene is 600 mmHg. **Q. 5.** Define: Green chemistry. Write two advantages of nanoparticle and nanotechnology. **Q. 6.** Explain the following terms: *(a) Substitutional impurity defect* *(b) Interstitial impurity defect* **Q. 7.** Write the chemical reactions for the following: *(a) Chlorobenzene is heated with fuming H2SO4* *(b) Ethyl bromide is heated with silver acetate* **Q. 8.** Define: Acidic buffer solution. Write the relationship between solubility and solubility product for Pbl2. **Q. 9.** What is the action of the following reagents on ethyl amine *(a) Chloroform and caustic potash* *(b) Nitrous acid* **Q. 10.** Calculate standard Gibbs energy change at 25°C for the cell reaction Cd (s)+Sn2 (aq) →Cd2 (aq) + Sn (s) E°Cd=-0.403V.E°Sn=-0.136V **Q. 11.** Write chemical reaction for the preparation of glucose from sucrose. Write structure of D-ribose. **Q. 12.** Define Extensive property. Calculate the work done during the expansion of 2 moles of an ideal gas from 10 dm³ to 20 dm³ at 298 K in vacuum. **Q. 13.** Write the reactions for the formation of nylon 6,6 polymer. **Q. 14.** Draw structures of the following compounds: *(a) chloric acid* *(b) peroxy disulphuric acid* ## SECTION -C Attempt any EIGHT of the following questions : **Q. 15.** Define Osmosis. How will you determine molar mass of non volatile solute by elevation of boiling point? **Q. 16.** Convert the following: *(i) Ethyl alcohol into ethyl acetate* *(ii) Phenol into benzene* *(iii) Diethyl ether into ethyl chloride* **Q. 17.** A weak monobasic acid is 10% dissociated in 0.05 M solution. What is percent dissociation in 0.15 M solution? **Q. 18.** Explain dehydrohalogenation reaction of 2-chlorobutane. Write use and environmental effect of CFC. **Q. 19.** 2000 mmol of an ideal gas expanded isothermally and reversibly from 20 L to 30 L at 300 K, calculate the work done in the process (R = 8.314 JK-¹ mol-1). **Q. 20.** What are interstitial compounds? Give the classification of alloys with examples. **Q. 21.** Draw labelled diagram of H2-O2 fuel cell. Write two applications of fuel cell. **Q. 22.** Explain formation of [Cof] 30 complex with respect to *(i) Hybridisation* *(ii) Magnetic properties* *(iii) Inner/outer complex* *(iv) Geometry* **Q. 23.** What is Pseudo first order reaction? Derive integrated rate law equation for zero order reaction. **Q. 24.** Explain Aldol condensation of ethanal. **Q. 25.** Explain anomalous behaviour of oxygen in group 16 with respect to: *(i) Atomicity* *(ii) Magnetic property* *(iii) Oxidation state* **Q. 26.** Write chemical reactions for the following conversions: *(a) Acetic acid into acetic anhydride* *(b) Acetic acid into ethyl alcohol* Write IUPAC name and structure of methylphenylamine. ## SECTION - D Attempt any THREE of the following questions : **Q. 27.** Show that, time required for 99.9% completion of a first order reaction is three times the time required for 90% completion. Give electronic configuration of Gd (Z=64). Write the name of nano structured material used in car tyres to increase the life of tyres. **Q. 28.** Derive relationship between AH and AU for gaseous reaction. Define: Vulcanization What is peptide bond? **Q. 29.** Silver crystallizes in fcc structure. If edge length of unit cell is 400 pm, calculate density of silver (Atomic mass of Ag = 108). Write a note on Haloform reaction. **Q. 30.** Define: Distereoisomers. Give cis and trans isomers of [Co(NH3)4Cl2]. What is reference electrode? Give reason: Bleaching action of ozone is also called dry bleach. **Q. 31.** Write Dow process for preparation of Phenol. What is the action of bromine water on phenol? Give reason: Group 16th elements have lower ionisation enthalpy compared to group 15th elements. Write two uses of dioxygen.