DAILY PRACTICE PROBLEMS (DPP) Subject : Physical/Inorg.Chemistry Date : DPP No. 11 Class : XIII Course : DPP No.1 Max. Time : 29 Total Time : 29 min. Single choice Objective ('–1' negative marking) Q.1 to Q.7 (3 marks 3 min.) [21, 21] Subjective Questions ('–1' negative marking) Q.8 (4 marks 4 min.) [4, 4] Match the Following (no negative marking) Q.9 (4 marks 4 min.) [4, 4] 1. 84 g of Iron (Fe) is reacted with sufficient amount of steam to produced 44.8 L, H2 gas at S.T.P. according to the following reaction, a Fe + b H O c Fe O + dH . The stoichiometric coefficients of the reaction is 2 (At. wt., Fe = 56, O = 16, H = 1) 3 4 2 (1) 4, 3, 1, 4 (2*) 3, 4, 1, 4 (3) 1, 4, 2, 3 (4) none of these Sol. Mole of Fe a = Mole of H2 d 84 / a = 56 1.5 2 44.8 / 22.4 d ⇒ a 3 a d d 4 So, Ans. B. 2. Which statement is wrong- (1*) Oxidation number of oxygen is +1 in peroxides (2) Oxidation number of oxygen is +2 in oxygen difluoride (3) Oxidation number of oxygen is 1 2 in superoxides (4) Oxidation number of oxygen is –2 in most of is compound Sol. Oxidation number of oxygen is (–1) in peroxide. 3. Which of the following is not a redox reaction? (1) Mg + N Mg N (2) MnO – + C O 2– Mn2+ + CO 2 3 2 4 2 4 2 (3) CuSO4 + Kl Cu + 2 + K2SO4 (4*) AgCl + NH3 [Ag(NH ) ] Cl Sol. Those reaction in which oxidation number of any element do not change not a redox reaction. AgCl + NH3 [Ag(NH3)2]Cl. 4. In the reaction, 2S O 2– + I S O 2– + 2I–, the eq. wt. of S O –2 is equal to its - (1) Mol. wt. (2*) Mol. wt./2 (3) 2 × mol. wt. (4) Mol. wt./6. Sol. I + 2S O 2– S O 2– + 2I–. molecular wt. M ES O2 – = = . 4 6 no.of electron gain or loss by per moleculeof oxidant or reductant 2 2S O 2– S O 2– + 2e– . 2 3 4 6 5. In the following change - 3Fe + 4H2O Fe3O4 + 4H2. If the atomic weight of iron is 56, then its equivalent weight will be - (1) 42 (2*) 21 (3) 63 (4) 84 0 Sol. 3 Fe + 4H2O 8 / 3 Fe3O4 + 4H2 3Fe + 4H O Fe O + 8H+ + 8e– 8 V.F. of Fe = 3 . EFe = Atomic mass V.F. 56 = 8 / 3 = 21. 6. How many millilitres of a 9 N H2SO4 solution will be required to neutralize completely 20 mL of a 3.6 N NaOH solution? (1) 18.0 mL (2*) 8.0 mL (3) 16.0 mL (4) 80.0 mL Sol. NNaOH = 3.6 ; VNaOH = 20 ; 3.6 20 NH2SO4 = 9 ; VH2SO4 = ? VH2SO4 = 9 = 8 mL. 7. Calculate the normality of an NaOH solution, 21.5 mL of which is required to convert 0.240 g of NaH2PO4 in a solution to monohydrogen phosphate. (1) 1.093 N (2*) 0.093 N (3) 0.048 N (4) 0.93 N Sol. Equivalent of NaOH = Equivalent of NaH2PO4 0.24 21.5 × 10–3 × N = 120 × 1 N = 0.093 8. Identify the oxidant and the reductant in the following reactions : (a) KMnO4 + KCl + H2SO4 MnSO4 + K2SO4 + H2O + Cl2 (b) FeCl2 + H2O2 + HCl FeCl3 + H2O (7) (–1) (2) (0) Ans. (a) KMnO4 + KCl + H2SO4 (7) MnSO4 + K2SO4 + H2O + Cl2 . (2) KMnO4
DAILY PRACTICE PROBLEMS (DPP) Subject : Physical/Inorg.Chemistry Date : DPP No. 11 Class : XIII Course : DPP No.1 Max. Time : 29 Total Time : 29 min. Single choice Objective ('–1' negative marking) Q.1 to Q.7 (3 marks 3 min.) [21, 21] Subjective Questions ('–1' negative marking) Q.8 (4 marks 4 min.) [4, 4] Match the Following (no negative marking) Q.9 (4 marks 4 min.) [4, 4] 1. 84 g of Iron (Fe) is reacted with sufficient amount of steam to produced 44.8 L, H2 gas at S.T.P. according to the following reaction, a Fe + b H O c Fe O + dH . The stoichiometric coefficients of the reaction is 2 (At. wt., Fe = 56, O = 16, H = 1) 3 4 2 (1) 4, 3, 1, 4 (2*) 3, 4, 1, 4 (3) 1, 4, 2, 3 (4) none of these Sol. Mole of Fe a = Mole of H2 d 84 / a = 56 1.5 2 44.8 / 22.4 d ⇒ a 3 a d d 4 So, Ans. B. 2. Which statement is wrong- (1*) Oxidation number of oxygen is +1 in peroxides (2) Oxidation number of oxygen is +2 in oxygen difluoride (3) Oxidation number of oxygen is 1 2 in superoxides (4) Oxidation number of oxygen is –2 in most of is compound Sol. Oxidation number of oxygen is (–1) in peroxide. 3. Which of the following is not a redox reaction? (1) Mg + N Mg N (2) MnO – + C O 2– Mn2+ + CO 2 3 2 4 2 4 2 (3) CuSO4 + Kl Cu + 2 + K2SO4 (4*) AgCl + NH3 [Ag(NH ) ] Cl Sol. Those reaction in which oxidation number of any element do not change not a redox reaction. AgCl + NH3 [Ag(NH3)2]Cl. 4. In the reaction, 2S O 2– + I S O 2– + 2I–, the eq. wt. of S O –2 is equal to its - (1) Mol. wt. (2*) Mol. wt./2 (3) 2 × mol. wt. (4) Mol. wt./6. Sol. I + 2S O 2– S O 2– + 2I–. molecular wt. M ES O2 – = = . 4 6 no.of electron gain or loss by per moleculeof oxidant or reductant 2 2S O 2– S O 2– + 2e– . 2 3 4 6 5. In the following change - 3Fe + 4H2O Fe3O4 + 4H2. If the atomic weight of iron is 56, then its equivalent weight will be - (1) 42 (2*) 21 (3) 63 (4) 84 0 Sol. 3 Fe + 4H2O 8 / 3 Fe3O4 + 4H2 3Fe + 4H O Fe O + 8H+ + 8e– 8 V.F. of Fe = 3 . EFe = Atomic mass V.F. 56 = 8 / 3 = 21. 6. How many millilitres of a 9 N H2SO4 solution will be required to neutralize completely 20 mL of a 3.6 N NaOH solution? (1) 18.0 mL (2*) 8.0 mL (3) 16.0 mL (4) 80.0 mL Sol. NNaOH = 3.6 ; VNaOH = 20 ; 3.6 20 NH2SO4 = 9 ; VH2SO4 = ? VH2SO4 = 9 = 8 mL. 7. Calculate the normality of an NaOH solution, 21.5 mL of which is required to convert 0.240 g of NaH2PO4 in a solution to monohydrogen phosphate. (1) 1.093 N (2*) 0.093 N (3) 0.048 N (4) 0.93 N Sol. Equivalent of NaOH = Equivalent of NaH2PO4 0.24 21.5 × 10–3 × N = 120 × 1 N = 0.093 8. Identify the oxidant and the reductant in the following reactions : (a) KMnO4 + KCl + H2SO4 MnSO4 + K2SO4 + H2O + Cl2 (b) FeCl2 + H2O2 + HCl FeCl3 + H2O (7) (–1) (2) (0) Ans. (a) KMnO4 + KCl + H2SO4 (7) MnSO4 + K2SO4 + H2O + Cl2 . (2) KMnO4