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Chemistry | ICSE Board | Grade 12 | 2017
Q. When ammonium chloride and ammonium hydroxide are added to a solution containing both Al3+ and Ca2+ ions, which ion is precipitated first and why?
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Q. Answer the following:
(1) What is the effect of temperature on ionic product of water (Kw)?
(2) What happen to the ionic product of water (Kw) if some acid is added to it?
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Q. The conjugate acid of HPO24 is:
  1. H3PO3
  2. H3PO4
  3. H2PO4
  4. PO34
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Q. In a face centered cubic lattice, atom (A) occupies the corner positions and atom (B) occupied the face centre positions. If one atom of (B) is missing from one of the face centered points, the formula of the compound is
  1. A2B5
  2. AB2
  3. A2B3
  4. A2B
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Q. Frenkel defect does not change the density of the ionic crystal whereas, Schottky defect lowers the density of ionic crystal. Give a reason.
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Q. The following electrochemical cell is set up at 298K:
Zn/Zn2+(aq)(1M)//Cu2+(aq)(1M)/Cu
Given EoZn2+/Zn=0.761V, EoCu2+/Cu=+0.339V
(1) Write the cell reaction.
(2) Calculate the emf and free energy change at 298K.
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Q. Fill in the blanks by choosing the appropriate word/words from those given in the brackets:
(iodoform, acetaldehyde, positive, greater, acidic, acetone, disaccharide, negative, increases, glucose, decreases, chloroform, polysaccharide, lactose, lesser, basic, cationic hydrolysis, anionic hydrolysis)
(i) Calcium acetate on heating gives _________ which gives _________ on heating with iodine and sodium hydroxide solution.
(ii) On dilution of a solution, its specific conductance __________ while its equivalent conductance ___________.
(iii) Sucrose is a __________ and yields upon hydrolysis, a mixture of ________ and fructose.
(iv) More __________ the standard reduction potential of a substance, the ___________ is its ability to displace hydrogen from acids.
(v) An aqueous solution of CH3COONa is __________ due to _________.
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Q. What is the difference between the order of a reaction and its molecularity?
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Q. Explain the following:
(i) Hydrolysis of ester (ethyl acetate) begins slowly but becomes fast after sometime.
(ii) The pH value of acetic acid increases on addition of a few drops of sodium acetate.
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Q. Match the following:
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Q. Write the formula of the following compounds:
(i) Potassium trioxalatoaluminate (III)
(ii) Hexaaquairon(II) sulphate.
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Q. Why the freezing point depression (ΔTf) of 0.4M NaCl solution is nearly twice than that of 0.4M glucose solution?
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Q. How many sodium ions and chloride ions are present in a unit cell of sodium chloride crystal?
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Q. Calculate the equilibrium constant (Kc) for the formation of NH3 in the following reaction:
N2(g)+3H2(g)2NH3(g)
At equilibrium, the concentration of NH3, H2 and N2 are 1.2×102, 3.0×102 and 1.5×102M respectively.
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Q. Lead sulphide has face centered cubic crystal structure. If the edge length of the unit cell of lead sulphide is 495pm, calculate the density of the crystal. (atomic weight Pb=207, S=32)
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Q. A solution of potassium chloride has no effect on litmus whereas, a solution of zinc chloride turns the blue litmus red. Give a reason.
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Q. Determine the freezing point of a solution containing 0.625g of glucose (C6H12O6) dissolved in 102.8g of water.
(Freezing point of water =273K, Kf for water =1.87K kg mol1, atomic weight C=12, H=1, O=16)
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Q. The polymer formed by the condensation of hexamethylenediamine and adipic acid is:
  1. Bakelite
  2. Teflon
  3. Dacron
  4. Nylon-6, 6
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Q. A solution containing 8.44g of sucrose in 100g of water has a vapour pressure 4.56mm of Hg at 273K. If the vapour pressure of pure water is 4.58mm of Hg at the same temperature, calculate the molecular weight of sucrose.
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Q. Name the law or principle to which the following observations confirm:
(1) When water is added to a 1.0M aqueous solution of acetic acid, the number of hydrogen ion (H+) increases.
(2) When 9650 coulombs of electricity is passed through a solution of copper sulphate, 3.175g of copper is deposited on the cathode (atomic weight of Cu=63.5).
(3) When ammonium chloride is added to a solution of ammonium hydroxide, the concentration of hydroxyl ions decreases.
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Q. Identify the order of reaction from each of the following units of rate constant (k):
(a) mol L1 sec1
(b) mol1 L sec1
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Q. What are the products formed when phenol and nitrobenzene are treated separately with a mixture of concentrated sulphuric acid and concentrated nitric acid?
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Q. The half life period of a first order reaction is 20 minutes. The time required for the concentration of the reactant to change from 0.16M to 0.02M is:
  1. 80 minutes
  2. 40 minutes
  3. 60 minutes
  4. 20 minutes
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Q. Explain why high pressure is required in the manufacture of sulphur trioxide by contact process. State the law or principle used.
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Q. Name the types of isomerism shown by the following pairs of compounds:
(i) [Cu(NH3)4][PtCl4] and [Pt(NH3)4][CuCl4]
(ii) [Co(Pn)2Cl2]+ and [Co(tn)2Cl2]+
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Q. A 0.15M aqueous solution of KCl exerts an osmotic pressure of 6.8 atm at 310K. Calculate the degree of dissociation of KCl. (R=0.0821Lit.atmK1mol1).
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Q. For a spontaneous reaction ΔGo and Eo cell will be respectively
  1. ve and +ve
  2. +ve and ve
  3. ve and ve
  4. +ve and +ve
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Q. Name the order of reaction which proceeds with a uniform rate throughout.
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Q. For the reaction: 2H2+2NO2H2O+N2, the following rate data was obtained:
S. No.[NO] mol L1[H2] mol L1Rate: mol L1 sec1
1 0.40 0.40 4.6×103
2 0.80 0.40 18.4×103
3 0.40 0.80 9.2×103
Calculate the following:
(1) The overall order of reaction.
(2) The rate law.
(3) The value of rate constant (k).
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Q. Specific conductivity of 0.20M solution of KCl at 298K is 0.025 S cm1. Calculate its molar conductivity.
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