DPP-51 to 52-(Physical)-Physical Chemistry

DAILY PRACTICE PROBLEMS (DPP) Subject : Physical/Inorg.Chemistry Date : DPP No. 51 to 52 Class : XIII Course : DPP No.51 DPP No.1 Total Marks : 38 Max. Time : 38 min. Single choice Objective ('–1' negative marking) Q.1 to Q.10 (3 marks 3 min.) [30, 30] Subjective Questions ('–1' negative marking) Q.11 to Q.12 (4 marks 4 min.) [8, 8] 1. The solubility of A X is y mol dm 3 . Its solubility product is : (1) 6 y4 (2) 64 y4 (3) 36 y5 (4) 4 y3 2. The solubility of sparingly soluble electrolyte MmAa in water is given by the expression :  (1) s =  Ksp m  a   (2) s =  Ksp 1/ m  a   (3) s =  Ksp m  a   (4) s =  Ksp 1/ m  a   mm aa   mm aa   ma am   ma am          3. Three sparingly soluble salts M2X, MX and MX3 have the solubility product are in the ratio of 4: 1 : 27. Their solubilities will be in the order (1) MX3 > MX > M2 X (2) MX3 > M2X > MX (3) MX > MX3 > M2X (4) MX > M2X > MX3 4. A particular saturated solution of silver chromate, Ag CrO , has [Ag+]= 5×10–5 and [CrO 2–] = 4.4×10–4 M. What is value of Ksp for Ag2CrO4 ? (1) 1.1 × 10–12 . (2) 1.5 × 10–12 (3) 2 × 10–6 (4) 1 × 1012. 5. If the solubility product of silver oxalate is 5 × 10–10, what will be the weight of Ag C O in 2.5 litres of a saturated solution ? (Ag = 108, C = 12, O = 16). 2 2 4 (1) 0.50 gm (2) 0.38 gm (3) 0.30 gm (4) 0.45 gm. 6. A student wants to prepare a saturated solution of Ag+ ion . He has got three samples AgCl (K = 10 10) , 13 11 AgBr (Ksp = 1.6 × 10 ) and Ag CrO (Ksp = 3.2 × 10 ) . Which of the above compound will be used by him using minimum weight to prepare 1 lit. of saturated solution. (1) AgCl (2) AgBr (3) Ag2 CrO4 (4) all the above . 7. If the solubility of Ag2SO4 in 10 M Na SO solution be 2 × 10 M then K of Ag SO will be: –2 –8 2 4 (1) 32 × 10–24 (2) 16 × 10–18 (3) 32 × 10–18 (4) 16 × 10–24 8. The solubility of CaF2 NaF solution. in water at 1518ºC is 2 × 10–4 mole/litre. Calculate K of CaF2 and its solubility in 0.1M (1) 3.5 × 108 mole/litre (2) 3.0 × 109 mole/litre. (3) 3.3 × 10–9 mole/litre (4) 4.0 × 107 mole/litre 9. Calculate F— in a solution saturated with respect of both MgF and SrF2. Ksp (MgF ) = 9.5 x 10-9, K (SrF ) = 4 x 10-9. (1) 3 × 10–3 M. (2) 4 × 10–2 M. (3) 3.5 × 10–3 M (4) 1 × 10–3 M. 10. A solution is saturated with respect to SrCO & SrF . The [CO 2] was found to be 1.2 x 103 M. The 3 2 3 concentration of F in the solution would be : K (SrCO ) = 10–9, K (SrF ) = 3 × 10–11. (1) 3 x 103 M (2) 2 x 102 M (3) 6 x 102 M (4) 6 x 107 M 11. Calculate the solubility of AgCl (s) in (a) pure water (b) 0.1 M NaCl (c) 0.01 M CaCl2 at 25º C . Ksp (AgCl) = 2.56  10 10. Comment on the influence of [ Cl ] on the solubility of AgCl. 12. Find the solubility of CaF2 in 0.5 M solution of CaCl2 and water. How many times in solubility in the second case greater than in the first ? Ksp (CaF ) = 3.2 × 10–11. DPP No.52 DPP No.2 Total Marks : 38 Max. Time : 38 min. Single choice Objective ('–1' negative marking) Q.1 to Q.11 (3 marks 3 min.) [33, 33] Subjective Questions ('–1' negative marking) Q.12 (4 marks 5 min.) [4, 5] 1. The standard oxidation potentials, E°, for the half-reaction are as Zn = Zn2+ + 2e– ; E° = + 0.76 V Fe = Fe2+ + 2e– ; E° = + 0.41 V the E°cell is - Fe+2 + Zn Zn2+ + Fe gSaA (1) –0.35 V (2) + 0.35 V (3) +1.17 V (4) – 1.17 V 2. From the following E° values of half cells - (i) A + e–  A¯ ; (iii) C¯ + 2e–  C3– ; E° = – 0.24 V E° = –1.25 V (ii) B¯ + e–  B2– ; (iv) D + 2e–  D2– ; E° = + 1.25 V E° = + 0.68 V What combination of two half cells would result in a cell with the largest potential (1) (ii) and (iii) (2) (ii) and (iv) (3) (i) and (iii) (4) (i) and (iv) 3. The Ni/Ni2+ and F–/F electrode potentials are listed as +0.25 V and –2.87 V respectively (with respect to the standard hydrogen electrode). The cell potential when these are coupled under standard conditions is (1) 2.62 V and dependent on the reference electrode chosen. (2) 3.12 V and independent of the reference electrode chosen. (3) 3.12 V and dependent on the reference electrode chosen. (4) 2.62 V and independent of the reference electrode chosen. 4. For the cell prepared from electrode A and B, electrode A : Fe3 Cr2O2 Cr3 , 0 red = + 1.33 V and electrode B : , E0 Fe = 0.77 V, which of the following statement is not correct ? (1) The electrons will flow from B to A (in the outer circuit) when connections are made. (2) The standard emf of the cell will be 0.56 V. (3) A will be positive electrode. (4) None of the above. 5. The standard reduction potentials at 25°C for the following half reactions are given against each - Zn2+(aq) + 2e¯ Zn(s), –0.762 V ; Cr3+(aq) + 3e¯ Cr(s), –0.740 V 2H+ + 2e¯ H (g), 0.00 V ; Fe3+ + e¯ Fe2+, 0.77 V Which is the strongest reducing agent - (1) Zn (2) Cr (3) H (g) (4) Fe3+(aq) 6. Hydrogen gas will not reduce - (1) heated cupric oxide (2) heated feric oxide (3) heated stannic oxide (4) heated aluminium oxide 7. Four colourless salt solutions are placed in separate test tubes and a strip of copper is dipped in each. Which solution finally turns blue ? (use data from electrochemical series) (1) Pb(NO3)2 (2) AgNO3 (3) Zn(NO3)2 (4) Cd(NO3)2 8. Red hot carbon will remove oxygen from the oxide XO and YO but not from ZO. Y will remove oxygen from XO. Use this evidence to deduce the order of activity of the three metals X, Y, and Z putting the most active first - (1) XYZ (2) ZYX (3) YXZ (4) ZXY 9. Two Ist order reactions have half-lives in the ratio 3 : 2. Then the ratio of time intervals t : t , will be? Where 2 t1 is the time period for 25% completion of the first reaction and t2 is time required for 75% completion of the second reaction. [log 2 = 0.3, log 3 = 0.477] (1) 0.199 : 1 (2) 0.420 : 1 (3) 0.273 : 1 (4) 0.311 : 1 10. Identify the correct order of wavelength of light absorbed for the following complex ions. [Co(H O) ]3+ ; Co(CN) ]3– ; [Co(I) ]3– ; [Co(en) ]3+ 2 6 6 6 3 I II III IV (1) III > I > IV > II (2) II > IV > I > III (3) III > I > II > IV (4) I > III > IV > II 11. Which one of the following complexes exhibit chirality ? (1) [Cr(ox) ]3 (2) cis - [PtCl (en)] (3) cis - [RhCl (NH ) ]– (4) mer - [Co(NO ) (NH ) ] 3 2 2 3 2 2 3 3 3 12. If you place the amounts given below in pure water, will all of the salt dissolve before equilibrium can be established, or will some salt remain undissolved ? (a) 4.96 mg of MgF2 in 125 ml of pure water, Ksp = 3.2 x 10-8 (b) 3.9 mg of CaF2 in 100 ml of pure water, Ksp = 4 x 10 -12 Also find the percentage saturation in each case. ANSWER KEY DPP No.-49 1. 1 2. 3 3. 3 4. 3 5. 9.08. 6. 2.76  10 5 mol Lt1. 7. (1) 4.92 (2) 7.56 8. 0.3 mole of C5H5NHCl should be added to 500 ml solution of C5H5N. 9. 4 10. 4 11. 1 ANSWER KEY DPP No.-50 1. 2 2. 3 3. 3 4. 3 5. 1 6. 3 7. 3 8. 3 9. 4 10. 2,3 11. 1,2,4

Comments

Popular posts from this blog

Planning to start your own coaching institute for JEE, NEET, CBSE or Foundation? Here's why not to waste time in developing study material from scratch. Instead use the readymade study material to stay focused on quality of teaching as quality of teaching is the primary job in coaching profession while study material is secondary one. Quality of teaching determines results of your coaching that decides success & future of your coaching while good quality study material is merely a necessary teaching aid that supplements your teaching (video in Hindi)

Physics-30.24-Physics-Solids and Semiconductors

Physics-31.Rotational Mechanics