CHEMISTRY-19-11- 11th (PQRS) space

REVIEW TEST-6 Class : XI Time : 100 min Max. Marks : 100 General Remarks: INSTRUCTIONS 1. The question paper contain 20 questions and 24 pages. All questions are compulsory. Please ensure that the Question Paper you have received contains all the QUESTIONS and Pages. If you found some mistake like missing questions or pages then contact immediately to the Invigilator. 2. Each question should be done only in the space provided for it, otherwise the solution will not be checked. 3. Use of Calculator, Log table and Mobile is not permitted. 4. Legibility and clarity in answering the question will be appreciated. 5. Put a cross ( × ) on the rough work done by you. 6. Last two pages are Extra pages. You may use them for any unfinished question(s) mentioning the page number with remark "continued on page " Name Father's Name Class : Batch : B.C. Roll No. Invigilator's Full Name USEFUL DATA Atomic weights: Al = 27, Mg = 24, Cu = 63.5, Mn = 55, Cl = 35.5, O = 16, H = 1, P = 31, Ag = 108, N = 14, Li = 7, I = 127, Cr = 52, K=39, S = 32, Na = 23, C = 12, Br = 80, Fe = 56, Ca = 40, Zn = 65.4, Pt = 195, Useful constant : h = 6.62 × 10–34 J sec. For Office Use ……………………………. Total Marks Obtained………………… Q.No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Marks Q.1 (a) The first ionisation energy of Mg is higher than that of Na, but on the other hand the second ionisation energy of Na is very much higher than that of Mg. Explain [2] (b) Select the one having lower first ionisation energy in each given pair with explanation (i) I and I– (ii) Ba and Sr (iii) Be and B [3] Q.2 Select those species from the following having X–X linkage (X-represent central atom) and draw their Lewis structure. [5] (i) H N O (ii) N O (iii) H P O (iv) S O2 2 2 2 2 5 4 2 5 2 7 (v) S O2 2 6 Q.3 Arrange the following in (a) order of increasing IE1 Mg, F, Na, Al (b) order of decreasing EA1 Na, Be, B, K (c) order of increasing ionic mobility in aq. solution Mg2+, Ba2+, Cs+, Al+3 [1.5+1.5+2] Q.4 With the help of EN values [ENH = 2.1, ENO = 3.5, ENA = 1.8, ENB = 2.6, ENC = 1.6, END = 2.8] answer the following questions for the compounds HOA, HOB, HOC, HOD (a) Compounds whose aqueous solution is acidic and order of their acidic strength [2.5] (b) Compounds whose aqueous solution is basic and order of their basic strength [2.5] Q.5 Write all the possible orbitals in each case (upto n = 3) which fulfill following condition [5] Case – I  having only one radial node Case – II  having XY plane as angular node Case – III  having only two maxima if a curve is plotted between radial probability density Case – IV  vs radial distance both case – I and case – II are fulfilled Q.6 Acompound of iron & chlorine is soluble in H2O. An excess of silver nitrate was added to precipitate the Cl– ion as AgCl. If a 10 gm of the compound gave 22.6 gm of AgCl. What is the formula of the compound. [5] Q.7 (a) Arrange in order of increasing solubility (i) Na2SO4, K2SO4, Rb2SO4 (ii) MgCO3, CaCO3, BaCO3 [2] (b) Solubilities of the halides of lithium & cesium was found to be in the following order (i) LiF < LiCl < LiBr (ii) CsF > CsCl > CsBr Justify the above observation with proper explanation [3] Q.8 (a) Draw the structure of the following compounds : [2] (i) Hydrogen phosphite ion (H2PO2–) (ii) Dihydrogen phosphate ion (H2PO4–) (b) Arrange in order of increasing magnitude of energy released in the formation of adduct (addition product) between BF3 & MH3 where M may be N, P, As. [3] Q.9 With the help of following information compare the reducing power of Na or Cs in aqueous solution. [5] Type of enthalpy change (kJ ) Na Cs H Sub 108 78  H I . E . 496 376  H H . E . – 406 – 276 Q.10 With the help of above information answer the following questions (1) HL.E. of AlCl3(s) will be . (2) HH.E. of Al+3(g) ion will be . (3) ΔHEA of [Al+3(g)] will be . (4) HBDE[Cl2] + HEA[Cl (g)] will be . [1+1+1+2] Q.11 The maximum amount of energy which can be obtained bya mixing 30 gm of carbon with 48 gm oxygen will be? Given:– C(s) + O2  CO2 H = – 80 kJ/mol 1 C(s) + 2 O2  CO H = – 50 kJ/mol [5] Q.12 Electron present in H atom jumps from energy level 3 to 1. Emitted photons when passed through a sample containing excited He+ ion causes further excitation to some higher energy level. Determine Z2 principal quantum number of initial excited level & higher energy level of He+. (Given En = –13.6 2 ) [5] Q.13 Find the number of diffusion steps required to separate the isotopic mixture initially containing some amount of H2 gas and 1 mol of D2 gas in a container of 3 lit capacity maintained at 24.6 atm & 27 °C to  w D   2  1 the final mass ratio  w H  equal to . (R = 0.082 Lt-atm/mol-K) [5] 2  Q.14 1 mole of CCl4 vapours at 27°C occupies a volume of 40 lit. If vander Waals constant are a = 24.6 L2 atm mol–1 and b = 0.125 Lmol–1. Calculate compressibility factor under (a) Low pressure region (b) High pressure region [Take R = 0.082 lit-atm/mol/K] [2.5+2.5] Q.15 A 500 ml solution was prepared by dissolving 28.5 gm of MgCl2 in water. If the density of MgCl2 solution is 1.2 gm/ml, calculate (a) Molarity of Cl– ion (b) Mole fraction of Mg2+ ion (c) Concentration in ppm of Mg2+ ion [1.5+1.5+2] Q.16 NO2 partially converts into NO, O2 and N2O4 according to following reaction. NO2(g) NO(g)  1 O 2 2 (g) 1 2 N2O4 (g) Pressure increases from 5 atm to 5.25 atm due to above reactions at constant temperature and the ratio of number of moles of O2 & N2O4 becomes 3/2. Calculate the final partial pressure of each gas in the final state. [5] Q.17 Two containers of equal volume containing equal masses of gas A (MA = 32) & gas B (MB = 16) separately are maintained at temperature T & 2T respectively. (A = 2B) Find (a) ratio of total translational K.E. of gas A& gas B. (b) ratio of the mean free path of gas A & gas B (c) ratio of the collision frequency of gas A& gas B [1.5+1.5+2] Q.18 A balloon containing 1 mole air at 1 atm initially is filled further with air till pressure increases to 3 atm. The initial diameter of the balloon is 1 m and the pressure at each state is proportion to diameter of the balloon. Calculate (a) No. of moles of air added to change the pressure from 1 atm to 3 atm. (b) balloon will burst if pressure increases to 7 atm. Calculate the number of moles of air that must be added after initial condition to burst the balloon. [2+3] Q.19 Photon having wavelength 12.42 nm was allowed to strike a metal plate having work function 25 eV. Calculate the (a) Maximum kinetic energy of photoelectrons emitted in eV. (b) Wavelength of electron with maximum kinetic energy in Å. (c) Calculate the uncertainity in wavelength of emitted electron if the uncertainity in the momentum is 6.62 × 10–28 Kg m/sec. (h = 6.62 × 10–34 J- sec.) [1.5+1.5+2] Q.20(a) A 40 ml sample of a mixture of H2 & O2 was placed in a gas burette at 27°C and 1 atm pressure. A spark was applied so that the formation of water was complete. The remaining pure gas that diffuses faster than N2 gas under similar condition had a volume of 10 ml at same temperature and pressure as given initially. What was the initial mole percent of H2 in the mixture? [2] Q.20(b) Air is pumped into the tubes of a bicycle at a pressure of 2 atm. The volume of each tube at this pressure is 2 lit. One of the tube get punctured and the volume of the tube reduces to 0.5 lit. Assuming temperature to be constant at 300 K and air behaving as an ideal gas, calculate the fraction of moles of air leaked out? [Take Atmospheric Pressure = 1 atm, R = 0.082 lit-atm/mol/K] [3] EXTRA PAGE