Chemistry-70.Phase-1-Subjective

FACULTY TRAINING TEST PHASE - I CHEMISTRY Time: 2 Hours Maximum Marks: 100 Instructions: 1. This paper consists of ELEVEN QUESTIONS only. 2. Attempt ALL questions. 3. Marks for each question is denoted in the right hand margin. 4. Use of Calculator is NOT PERMITTED Name : 00000000000000000 Subject : 00000000000 1. a) A gas cylinder containing L.P.G. can withstand a pressure of 15.6 atmosphere. The pressure gauge of cylinder indicates 12.5 atmosphere at 27°C. At what temperature cylinder will explode? b) Calculate the density of N2 at 150°C and 1000 mm Hg pressure [6+4] 2. a) How long will a mixture containing 40% ozone and 60% oxygen by volume take to diffuse through a porous plug if pure oxygen takes 30 mins under the same condition? b) The best vacuum so for attained in laboratory is 10–10 mm of Hg. How many molecules of gas remains per cc at 20°C in this vacuum ? [6+4] 3. a) Calculate percentage ionic character of AB molecule assuming its dipole moment to be 1.03 D and bond length 127 pm. (Debye, D = 3.3356  10–30 C.m, pm. = 10–12 m and unit charge = 1.6  10–19 C). [3] b) Arrange the following in increasing order of the character as instructed in bracket to each i) NH3,PH3,AsH3 and SbH3 (bond angle) ii) LiF, LiCl, LiBr and LiI (covalent character) iii) H2O, H2S and H2Te ( boiling point) iv) F, Cl, Br and I (electron affinity) v) Al3+, Mg2+, F–, O2– and Na+ (size) vi) NaF, NaCl, NaBr and NaI (melting point) vii) Na, Mg, Al and Si (2nd I.P.) [7] 4. A mixture of 20 ml of CO, CH4 and N2 was burnt in excess of O2 resulting in reduction of 13 ml of volume. The residue gas was then titrated with KOH solution to show a contraction of 14 ml in volume. Calculate volume of CO, CH4 and N2 in mixture. All measurements are made at constant pressure and temperature. [6] 5. i) Define the shape and hybridization in XeOF4 and XeOF6 ii) Why O2 is paramagnetic in nature. [6+2] 6. Balance the following equations a) + 3H2O MnO2 + O2 b) Cu3P + Cu+2 + H3PO4 + Cr+3 [5+5] 7. On the basis of Heisenberg's uncertainty principle, show that the electron cant exist in side the nucleus. [5] 8. a) A 2.36 g sample of dolomite containing CaCO3 and MgCO3 were dissolved in 700 mL of decinormal solution of HCl. The solution was diluted to 2.5L and 25mL of this solution required 20 mL 0.01N NaOH solution for complete neutralisation. Compute the composition of the ore. [7] b) A sample of hydrazine sulphate (N2H6SO4) was dissolved in 100 mL water 10mL of this solution was reacted with excess FeCl3 solution and warmed to complete the reaction. Ferrous ion formed was estimated and it required 20 ml of M/50 KMnO4 solution. Estimate the amount of sulfate in one litre of solution. [7] 9. A mixture contains NaCl and an unknown chloride MCl. i) 1 g of this is dissolved in water. Excess of acidified AgNO3 solution is added to it. 2.567 g of a white precipitate is formed. ii) 1 g of the original mixture is heated to 300°C. Some vapours come out which are absorbed in acidified AgNO3 solution.1.341 g of a white precipitate is obtained. Find the molecular weight of the unknown chloride. [10] 10. a) 1.6 g of Pyrolusite ore was treated with 50cm3 of 1.0 N, oxalic acid and some sulfuric acid. The oxalic acid left undecomposed was raised to 250 cm3 in a flask. 25cm3 of this solution when titrated with 0.1N KMnO4 required 32cm3 of the solution. Find out the percentage of pure MnO2 in the sample and also the percentage of available oxygen. [6] b) A mixture of pure K2Cr2O7 and pure KMnO4 weighing 0.561 g was treated with excess of KI in acid medium. Iodine liberated required 100 mL of 0.15 N of hypo solution for exact oxidation. What is the percentage of each in the mixture? [8] 11. a) If uncertainties in the measurement of position and momentum are equal, calculate uncertainty in the measurement of velocity. [3] b) What accelerating potential is needed to produce an electron beam with an effective wavelength of 0.090Å? [7] 6