Download NEET-UG 2013 Answer Key (Code - X) - Bansal Classes

Q.18 Which of the following lanthanoid ions isdiamagnetic ?At nos. Ce = 58, Sm = 62, Eu = 63, Yb = 70(1) Sm 2+ (2) Eu 2+(3) Yb 2+ (4) Ce 2+Ans. 3Q.19 6.02 × 10 20 molecules of urea are present in100 mL of its solution. The concentration ofsolutionis:(1) 0.01 M (2) 0.001 M(3) 0.1 M (4) 0.02 MAns. 12Q.20 Based on equation E = – 2.178 × 10 –18 J Z2 n certain conclusions arewritten. Which of themis not correct ?(1) Larger the value of n, the larger is the orbitradius.(2) Equation can be used to calculate thechange in energy when the electron changesorbit(3) For n = 1, the electron has a more negativeenergythan it does for n = 6 which means thatthe electron is more loosely bound in thesmallest allowed orbit(4)Thenegative sign in equationsimplymeansthattheenergyof electron boundtothe nucleusis lower than it would be if the electrons wereat the infinite distance from the nucleus.Ans. 3Q.21 An excess ofAgNO 3is added to 100 mLof a0.01 M solution ofdichlorotetraaquachromium(III) chloride. Thenumber of moles ofAgCl precipitated wouldbe :(1) 0.002 (2) 0.003(3) 0.01 (4) 0.001Ans. 4Q.22 KMnO 4can be prepared from K 2MnO 4asper the reaction :3MnO 4 2– + 2H 2O 2MnO 4 – + MnO 2+4OH – . The reaction can go to completion byremoving OH – ions byadding :(1) KOH (2) CO 2(3) SO 2(4) HClAns. 2Q.23 Which of the following compounds will notundergo Friedal–Craft's reaction easily:(1) Xylene (2) Nitrobenzene(3)Toluene (4) CumeneAns. 2Q.24 Which of these is least likely to act as a Lewisbase ?(1) F – (2) BF 3(3) PF 3(4) COAns. 2Q.25 The basic structural unit of silicates is :(1) SiO4–4(2) SiO2–3(3) SiO2–4(4) SiO –Ans. 1Q.26 Maximumdeviationfromidealgas is expectedfrom:(1) N 2(g) (2) CH 4(g)(3) NH 3(g) (4) H 2(g)Ans. 3Q.27 Which is the strongest acid in the following ?(1) HClO 3(2) HClO 4(3) H 2SO 3(4) H 2SO 4Ans. 2