(11^th CLASS -2012)
CHEMISTRY, GROUP FIRST
TIME: 20 MINUTES
OBJECTIVE
NOTE: You have four choices for each objective type question as A,B,C and D The choice which you think is correct, fill that circle in front of that question number, Use marker or pen to fill the circles. Cutting or filling two or more circles will result in zero mark in that question. Attempt as many questions as given in objective type question paper and leave others blank.. Write the letterA,B,C or D in the column (Write correct option) against each question. If there is a contradiction in the bubble and hand written answer, bubble option will be considered correct.

QUESTION NO.1

• 27 g of Al will react completely with how much mass of O₂ to produce AL₂O_2.
  
  (A) 8 g of oxygen
  (B) 16 g of oxygen
  (C) 32 g of oxygen
  (D) 24 g of oxygen
  
  
• Isotopes differ in
  
  (A) Arrangement of electrons
  (B) Chemical properties
  (C) properties which depend upon mass
  (D) The extent to which they may be affected in electromagnetic field.
  
  
• Solvent extraction method is a useful technique for separation when the product to be separated is
  
  (A) Non-volatile or thermally stable
  (B) Volatile or thermally unstable
  (C) Non-volatile or thermally unstable
  (D) Volatile or thermally stable
  
  
• Number of molecules in one dm³ of H₂O is close to

(A)  ×10²³
(B)  ×10²³
(C)  ×10²³
(D)  55.6×6.02×10²³

• The order of rate of diffusion of the gases NH₃, SO₂, C1₂ and CO₂ is
  
  (A) NH₃> CO₂ > SO₂ > Cl₂
  (B) NH₃ > SO₂ > C1₂ > CO₂
  (C) C1₂ > SO₂ > CO₂ > NH₃
  (D) NH₃> CO₂ > C1₂ > SO₂
  
  
• When water freezes at 0⁰C, its density decreases due to
  
  (A) Cubic structure of ice
  (B) empty spaces present in the structure of ICC
  (C) Change of bond lengths
  (D) Change of bond angles
  
  
• Amorphous solids
  
  (A) Have sharp melting point            
  (B) Undergo clean cleavage when cut with knife
  (C) Have perfect arrangement of atoms
  (D) Can possesses small regions of orderly arrangement of atoms
  
  
• The velocity of photon is
  
  (A) Independent of its wavelength
  (B) Depends on its wavelength
  (C) Equal to square of its amplitude
  (D) Depends on its source
  
  
• Orbitals having same energy are called
  
  (A) Hybrid orbital
  (B) Valence orbitals
  (C) Degenerate orbitals
  (D) d-orbitals
  
  
• The number of bonds in nitrogen molecule is
  
  (A) One Ϭ and one π
  (B) One Ϭ and two π               
  (C) Three Ϭ only
  (D) Two Ϭ and one π
  
  
• Which of the hydrogen halides has the highest percentage of ionic character ?
  
  (A) HCL
  (B) HBR
  (C) HF
  (D) HI
  
  
• For the reaction NaOH+HCL NaC1+ H₂O the change in enthalpy is called
  
  (A) Heat of reaction
  (B) Heat of formation
  (C) Heat of neutralization
  (D) Heat of combustion.
  
  
• The pH of 10^-3 mol dm^-3 of an aqueous solution of H₂SO₄ is
  
  (A) 3.0
  (B) 2.7             
  (C) 2.0
  (D) 1.5
  
  
• A solution of glucose is 10 % W/v . The volume in which I g mole of it dissolved will be
  
  (A) 1 dm³
  (B) 1.8 dm³
  (C) 200 cm³
  (D) 900 cm³
  
  
• Which of the following statement is not correct about galvanic cell?
  
  (A) Anode is negatively charged
  (B) Reduction occur at anode
  (C) Cathode is positively charged
  (D) Reduction occur at cathode
  
  
• Stronger is the oxidizing agent , greater is the
  
  (A) Oxidation potential
  (B) Reduction potential
  (C) Redox potential
  (D) EMF of the cell
  
  
• The rate of reaction
  
  (A) Increases as the reaction proceeds
  (B) Decreases as the reaction proceeds
  (C) Remains the same as the reaction proceeds
  (D) Speed up as the reaction proceeds

SUBJECTIVE
(SECTION –I)

QUESTION NO. 2

Write short answers any Eight questions of the following        16

• What is the function of 50 % KOH and Mg(C1O₄)₂ in combustion analysis?
• Calculate moles of chlorine atoms in 0.822 gram of C₂H₄CL₂ ?
• N₂ and CO have the same number of electrons protons and neutrons, Justify it?
• Write any four characteristics of an ideal solvent?
• What is sublimation ?Name any two sublimates?
• State Graham's law of diffusion and write its mathematical form?
• The plot of PV versus P is a straight line at constant temperature and with a fixed number of moles of an ideal gas? 
• Give two applications of plasma?
• What are causes for deviation from ideality of gases?
• Evaporation causes cooling. Explain with reason?
• Why HF is weaker acid than HCL?
• Ionic crystals do not conduct electricity in the solid state. Explain.

3. Write short answers any Eight questions of the following. 16

• Define hund,s rule and Pauli's exclusion principle.
• Cathode rays do not depend upon the nature of the gas, Discuss.
• Define Moseley's law. Give its mathematical expression.
• Define Ionization energy, Give its trend in periodic table.
• Bond distance is the compromise distance between two atoms. Give reason.
• Define system and surroundings with examples.
• Differentiate between exothermic and endothermic reactions.
• Burning of a candle is spontaneous reactions, Discuss.
• Define molarity and moiality.
• In summer the antifreeze solutions protect the radiations from boiling over How ?
• Aqueous solution of CH₃COONa is basic in nature. Discuss.
• Differentiate between oxidation and reduction reactions.

4. Write short answers any Six questions of the following: 12

• Differentiate between bonding and anti bonding molecular orbitals.
• Why CS₂ molecule is linear while SO₂ is angular ?
• Give two uses of buffers.
• Why solubility of glucose in water is increased by increasing temperature.
• Define pH and pOH.
• What is effect of catalyst on equilibrium constant?
• What is critical solution temperature? Give exam?
• Give two pairs of liquids which form ideal solution.
• A finely divided catalyst may prove more effective why.

SECTION-II

Attempt any Three questions from this section                                          (8×3=24)

Q NO.5
(a) How can you determine relative atomic masses of isotopes by mass spectrometry   (4)
(b)  How vapour  pressure is measured by Manometer  method.  (4)
Q NO.6
(a) Explain valence bond theory (VBT) with examples showing the overlapping of different orbitals. (4)
(b) Neutralization of 100 Cm³ of 0.5m  NaOH at 25⁰C with 100 Cm³ of 0.5 m HC1 at 25⁰ C raised the temperature of the reaction mixture to 28.5⁰C , Find the enthalpy of neutralization. Specific heat of water = 4.2 JK^-1g^-1 (4)

Q NO.7
(a) What is J.J Thomson's experiment for determining e/m value of electron. Evaluate mass of electron from this experiment  (4)
(b) Calculate the mass 1dm³ of NH₃ gas at 30⁰C and 1000 mm Hg pressure considering that NH₃ is behaving ideally.  (4)

Q NO.8
(a) Define Le. Chatelieri's Principle. Discuss effect of
(i) Change in volume
(ii) Change in temperature on the formation of ammonia
(b) Balance the following equation by-ion electron method in acidic medium (4)
Cl +  MnO_{4 →}   Cl₂+ Mn²⁺  

Q NO.9
(a) Write note on hydration reaction   (4)
(b) On which factors rate of chemical reaction depend and explain the effect of concentration of reactants. (4)