
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

ISC Class XI Prelims 2024 : Chemistry (Delhi Public School (DPS), Newtown, Kolkata)

6 pages, 0 questions, 0 questions with responses, 0 total responses,

Snigdha Patra
Delhi Public School (DPS), Newtown, Kolkata

+Fave Message

Profile Timeline Uploads

Home > snigdha_patra > F Also featured on: School Page

Formatting page ...

DELHI PUBLIC SCHOOL NEWTOWN SESSION 2024-25 FINAL EXAMINATION CLASS: XI SUBJECT: CHEMISTRY [SET A] FULL MARKS: 70 TIME : 3 HOURS Instructions to Candidates You are allowed additional 15 minutes for only reading the question paper. You must NOT start writing during the reading time. This question paper has 6 printed pages. It is divided into four sections and has 21 questions in all. All questions are compulsory. Answer all questions. Section A has fourteen subparts. Each question carries 1 mark. While attempting Multiple Choice Questions in Section A, you are required to write only ONE option as the answer. Section B has ten questions. Each question carries 2 marks. Section C has seven questions. Each question carries 3 marks. Section D has three questions. Each question carries 5 marks. Internal choices have been provided in one question each in Sections B, C and D. The intended marks for questions are given in brackets [ ]. All working, including rough work, should be done on the same sheet as, and adjacent to the rest of the answer. Balanced equations must be given wherever possible and diagrams where they are helpful. When solving numerical problems, all essential workings must be shown. In working out problems, use the following data: Gas constant R = 1.987 caldeg-1 mol-1 =8.314 JK-1 mol-1 = 0.0821 dm3atm K-1 mol-1 1l atm= 1dm3atm =101.3 J = 1 Faraday = 96500 Coulombs Avogadro s number = 6.023 x 1023 (This question paper contains six printed pages) SECTION A 14 MARKS Question 1 (A) Fill in the blanks by choosing the appropriate word(s) from those given in the brackets: [4 1] [ Lewis acid, unsymmetrical, electron, pressure, enthalpy, Lewis base, temperature, symmetrical, methane, shape, ethane, orientation ] (i) AlCl3 is a __________because it is an __________ deficient molecule. (ii) Heat capacity at constant pressure is the rate of change of __________ with __________ . A/1 (iii) Wurtz reaction is used for the preparation of _________ alkanes except __________ . (iv) 3px , 3py and 3pz orbital of an atom have identical __________ but differ in their __________ . (B) Select and write the correct alternative from the choices given below: [7 1] (i) Which of the following molecule shows intramolecular hydrogen bonding? (a) Phenol (b) Benzoic acid (c) p-nitrophenol (d) o-hyroxy benzaldehyde (ii) Relation between magnetic quantum number (m) and azimuthal quantum number (l) is: (a) l = (m+1)/2 (b) l = (m-1)/2 (c) l = (2m+1)/2 (d) l = (m+2)/2 (iii) Element with valence shell electronic configuration as (n-1)d6ns2 is placed in which of the following group and block of elements? (a) 2, s-block (b) 8, d-block (c) 8, s-block (d) 6, d-block (iv) The final product of the following reaction is: Sunlight C6H6 + Cl2 (a) C6H5Cl (c) p - C6H4Cl2 (v) ? (b) o - C6H4Cl2 (d) C6H6Cl6 In which of the following reactions there is no change in the hybridization of the central atom in the final product? (a) AlCl3 + Cl- AlCl41(b) BF3 + NH3 F3B.NH3 (c) SF4 + F2 SF6 (d) BF3 + F- BF41- (vi) Assertion: Na+ and Al+3 are isoelectronic but the magnitude of the ionic radius of Al+3 is less than that of Na+ Reason: The magnitude of effective nuclear charge of the outer shell electrons in Al+3 is greater than that in Na+. (a) Both assertion and reason are true and reason is the correct explanation of assertion. (b) Both assertion and reason are true but reason is not the correct explanation for assertion. (c) Assertion is true but reason is false. (d) Assertion is false but reason is true. (vii) Assertion: Acetylene on treating with NaNH2 gives sodium acetylide and ammonia. Reason: sp-Hybridized carbon atoms of acetylene are considerably electronegative. (a) Both assertion and reason are true and reason is the correct explanation of assertion. (b) Both assertion and reason are true but reason is not the correct explanation for assertion. (c) Assertion is true but reason is false. (d) Assertion is false but reason is true. A/2 (C) Read the passage given below and answer the questions that follow: [3 1] Benzene is an ideal aromatic compound. Like benzene, there are a large number of other compounds which are aromatic in character. The most characteristic reactions of aromatic compounds are electrophilic substitution reactions which includes halogenation, nitration, sulphonation and Friedel-Craft s reactions. (i) Write a short note on nitration of benzene. (ii) Write the reaction mechanism of Friedel-Craft alkylation of benzene to form toluene. (iii) Draw the resonating structures of nitrobenzene. SECTION B 20 MARKS Question 2 [2] Calculate the wavelength of the spectral line in Lyman series corresponding to n2=3. Given [R=109677 cm-1]. Question 3 [2] Calculate molality of sulphuric acid in which the mole fraction of water is 0.85. Question 4 [2] The molecular mass of an organic compound is 78 and its percentage composition is 92.4% C and 7.6% H. Determine the molecular formula of the compound [At masses: C=12, H=1]. Question 5 State which one of the following is Aromatic, Non-aromatic and Anti-aromatic: [2] Question 6 [2] The element Z=117 has recently been discovered while element with Z=120 has not yet been discovered. In which group would you place these elements and also give the electronic configuration in each case. Question 7 [2] Find the oxidation number of the underlined species. (i) CrO42- (ii) [Fe(CO)4] (iii) H2SO4 (iv) Cr2O72- Question 8 [2] 0.3 g of an organic chloro compound gave 0.574 g of silver chloride in Carius estimation. Calculate the percentage of chlorine present in the compound. [At masses Ag=108, Cl=35.5]. Question 9 [2] (i) (a) Consider the following compounds in the liquid form: O2, H2O, CCl4, CHCl3 and C6H6.When a charged comb is brought near their flowing stream, how many of them show deflection as per the following figure. A/3 b) Write which one out of O2+ and O22- is more stable on the basis of bond order calculation? OR (ii) Give reason for the following: a) Ethanol has higher boiling point than diethyl ether. b) Though F atom is more electronegative than H atom but the dipole moment of NF3 is smaller than that of NH3. Question 10 A+B C + D ; H= -10000 J mol-1, S= -33.3 J mol-1 K-1. (i) At what temperature the reaction will occur spontaneously from left to right? (ii) At what temperature, the reaction will reverse? [2] Question 11 Predict the major product of the following reactions: [2] SECTION C 21 MARKS Question 12 Draw the MO diagram of O2+. Write its magnetic property and bond order. [3] Question 13 How would you convert the following: (i) 3- methylbutyne from ethyne (ii) trans pent-2-ene from ethyne (iii) m-nitrobromobenzene from benzene [3] Question 14 [3] (i) What is buffer capacity? (ii) The ionization constant of acetic acid is 1.74 x 10-5. Calculate the degree of dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ions in the solution and its pH? A/4 Question 15 [3] nd (i) State the 2 law of thermodynamics. (ii) If water vapour is assumed to be perfect gas, molar enthalpy change at 1 bar and 373K is 41 kJ / mol. Calculate the internal energy change when (i) 1 mol of water is vaporised at 1 bar pressure and 373 K. (ii) 1 mol of water is converted into ice. Question 16 [3] (i) (a) State Pauli s exclusion principle. (b) Calculate the uncertainty in position of an electron if uncertainty in velocity is 5.7x105 m/s. (Mass of electron= 9.1x10-31 kg, h=6.626x10-34 Js). OR (ii) (a) Differentiate between matter and electromagnetic waves. (b) If uncertainties in the measurement of position and momentum of an electron are found to be equal in magnitude, what is the uncertainty in the measurement of velocity of the electron? Comment on the result obtained. Question 17 [3] (i) State Hess s law of constant heat summation. (ii) The combustion of 1 mole of benzene takes place at 298K and 1 atm. After combustion, CO2 (g) and H2O (l) are produced and 3267 kJ of heat is liberated. Calculate the standard enthalpy of formation of benzene. Standard enthalpies of formation of CO2 (g) and H2O (l) are -393.5 kJ / mol and -285.83 kJ / mol respectively. Question 18 Write the hybridization of the underlined species and give the shape of the molecules. (a) CO32(b) PCl3 (c) IF5 [3] SECTION D 15 MARKS Question 19 (i) Balance the following reaction by ion electron method. [5] N2H4 + ClO3NO + Cl- (in basic medium) (ii) Balance the following reaction by oxidation number method. Mg + HNO3 Mg(NO3)2 + N2O + H2O Question 20 [5] (i) Prove that the pressure necessary to obtain 50 % dissociation of PCl5 at 500 K is numerically equal to three times the value of the equilibrium constant Kp. (ii) On the basis of Le Chatelier s principle state whether the following reactions will shift towards forward or backward direction: A(g) + B(g) C(g) + heat (a) Ne added at constant pressure (b) Temperature is decreased (c) Pressure is increased A/5 Question 21 (i) Write the IUPAC nomenclature of the following compounds: (a) [5] (b) (c) (ii) Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile. (a) Chlorobenzene, 2,4-Dinitrochlorobenzene, p-nitrochlorobenzene (b) Toluene, p-H3C-C6H4-NO2, p-NO2-C6H4-NO2 OR (iii) Draw the bond line notation of the following organic compounds: (a) 5-Bromohexanoyl chloride (b) 2-Methylpropan-2-amine (c) Pentane-2,4-dione (iv) An alkyl halide C5H11Br (A) reacts with ethanolic KOH to give an alkene (B), which reacts with Br2 to give a compound (C), which on dehydrobromination gives an alkyne (D). On treatment with sodium metal in liquid ammonia, one mole of (D), gives one mole of sodium salt of (D) and half mole of hydrogen gas. Complete hydrogenation of (D) yields a straight chain alkane. Identify (A), (B), (C) and (D). A/6

Formatting page ...

snigdha_patra chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: