May 2011 - Career Point

16. Half a mole of photon is used to break the O 3molecule completely according to I st reaction. O 2produced in this reaction dissociates according to2 nd reaction, then what is the total energy requiredin KJ to carry out the dissociation of O 2 .(A) 384 KJ(B) 280 KJ(C) 480 KJ(D) 300 KJThis section contains 7 questions (Q.17 to 23).+4 marks will be given for each correct answer andno negative marking. The answer to each of thequestions is a SINGLE-DIGIT INTEGER, rangingfrom 0 to 9. The appropriate bubbles below therespective question numbers in the OMR have to bedarkened. For example, if the correct answers toquestion numbers X, Y, Z and W (say) are 6, 0, 9 and2, respectively, then the correct darkening of bubbleswill look like the following :X Y Z W012345678901234567890123456789012345678921. Find number of 120º bond angles in O = CF 2 .22. Give number of H-atoms in H 2 C = SF4 which arein plane of axial F-atoms.23. For an element Z eff for its outermost electron is3.55. If atomic radius of element is 0.75 Å, thenfind out its electro negativity.MATHEMATICSQuestion 1 to 7 are multiple choice questions. Eachquestions has four choices (A), (B), (C) and (D), out ofwhich ONLY ONE is correct.1– sin 2θ + cos 2θ1. If f (θ) =, then value of2cos 2θf (11º) f (34º) equals -13(A) (B) 2 4(C) 41(D) None of these2. If 3 ≤ a < 4 then value ofsin –1 (sin [a]) + tan –1 (tan [a]) + sec –1 (sec[a])(where [.] denotes greatest integer function) is -(A) 2π (B) 2π – 3(C) 3 (D) 2π + 317. A compound exists in the gaseous phase both asmonomer (A) and dimer (A 2 ). The molecularweight of A is 60. In an experiment 240 g of thecompound was confined in a vessel of volume32.84 litre and heated to 127º C. Calculate thepressure (in atm) developed if the compound existsas dimer to the extent of 50% by weight underthese conditions.18. Li 2+ ion in its ground state absorbs a photon ofenergy 183 electron volt. Electron of Li 2+ ionstrikes the He + ion. (in Å) after being struck byelectron of Li 2+ ion.3. If sum of all solutions of equation3cot 2 kπθ + 10 cotθ + 3 = 0 in [0, 2π] is 2k ∈ I then k equals -(A) 3 (B) 6(C) 10 (D) 154. Range of k for whichk cos 2 x – k cos x + 1 ≥ 0 ∀ x ∈ R is -1(A) k < – (B) k > 42where19. First ionization energy of Li is 13.6 eV. If it isassumed that outermost electron of Li revolvesunder the influence of nucleus which is shielded byinner two electrons in first orbit of Li, then find outby what amount of charge inner two electronsshield the nucleus?20. A photon of 50 eV energy strikes a metal surface(having work function 1.64 eV). Photoelectronejected from metal with maximum kinetic energystrikes He + ion (in ground state).Find out de-Broglie wavelength of electron of He +ion finally in Å.(C) – 21 ≤ k ≤ 4(D) None of these5. If sin (sin x + cos x) = cos (cos x – sin x ) thenlargest possible value of sin x is -1(A)(B) 12(C)16 – π42(D) 4πXtraEdge for IIT-JEE 58 MAY 2011