RAWALPINDI BOARD 2014
CHEMISTRY
PART-I
Time: 20 MM.
(Objective Part)
Marks: 17
Note: You have four choice 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.

• The born-Haber cycle is the best application of----------- law:

(a) Boyle's
(b) Dalton's
(c) Hess's
(d) Graham's

• Acid having Ka>1 will be:

(a) Weak
(b) Very weak
(c) Moderate
(d) Strong

• In the presence of common ion, the ionization of an electrolyte will:

(a) Increase
(b) Decrease
(c) No affect
(d) Moderate change

• Melting point of Ice can be lowered by the use of:

(a) LiCl
(b) BeC1₂
(c) NaCl
(d) AgCl

• In silver Oxide battery, the cathode is made up of:

(a) AgO
(b) Ag₂O
(c) Ag₂O₃
(d) Ag

• Oxidation number of phosphorous in the compound (HPO3) is:

(a) +3
(b) +4
(c) +5
(d) +6

• Glucose can be converted into ethanol by an enzyme:

(a) Lipase
(b) Zymase
(c) Sucrase
(d) Urease

• Palladium has Isotopes:

(a) 6
(b) 7
(c) 8
(d) 9

• The largest number of molecules are present in:

(a) 3.6g of  H₂O
(b) 4.8g of C₂H₅OH
(c) 2.8g of CO
(d) 5.4g of N₂O₅

• During paper chromatography the stationary phase is:

(a) Solid
(b) Liquid
(c) Gas
(d) Plasma

• Formula used for the conversion of "F in to "C is:

(a) °F = 9 / 5(0C) + 32
(b) 0C= 5/ 9[0F — 32]
(c) "F = 5/ 9("C)+ 32
(d) "C= 9/ 5[0F —32]

• The process in which liquid can be made to boil at low temperature is known as -----------distillation.

(a) Simple
(b) Thermal
(c) Steam
(d) Vacuum

• The Axes (unit cell length) for Cu is:

(a) a≠b=c
(b) a≠b≠c
(c) a=b≠c
(d) a=b=c.

• When fast neutron carry nuclear reaction with nitrogen it ejects particles:

(a) α
(b) β
(c) γ
(d) δ

• Orbitals having same energy are called:

(a) Hybrid
(b) Valence
(c) Mixed
(d) Degenerate

• In methanol, bond between carbon and oxygen is:

(a) Ionic
(b) Nonpolar
(c) Polar
(d) Co-ordinate

• The molecule having zero dipole moment is:

(a) NH₃
(b) CHO₃
(c) H₂O
(d) BF₃

Time: 3:10 Hours
(Subjective Part)
Marks: 83
Section-II 

2. Attempt any EIGHT short questions.

• How the molecular ions can be generated? Give two examples of such ions.
  
• Why in an experimental work, one or more reactants is/are deliberately used in excess quantity?
  
• Define the molecular formula. How is it related to the empirical formula?
  
• Why the boiling point of water seems to be more affected by hydrogen bonding than that of HF?
  
• How the liquid cystals help in the detection of the blockage in veins and arteries?
  
• The transition temperature is shown by elements having allotopic forms and the compounds showing polymorphism. Justify it.
  
• Write down any two methods of drying of the cystals.
  
• Define:
  Sublimation
  Distribution Law
  
• Convert 40°C into °F.
  
• Define critical temperature and the critical volume of a gas.
  
• Write down two characteristics of plasma. Why metals are malleable and ductile?

3. Attempt any EIGHT short questions.

• The velocity of electrons In higher orbits Is less than that' In the lower orbit of an atom give reason.
  
• The e/m values for positive rays are different for different gases, but that of cathode rays obtained from different gases is the same. Give reasons.
  
• Why the lone pair electrons repel strongly than the bond pair of electrons?
  
• The dipole moment of CO₂ and CS₂ is zero, but that of SO₂is 1.61D. Give reasons.
  
• Why the covalent compounds show isomerism, but ionic compound does not? How the change of temperature disturbs both the equilibrium position and equilibrium
• constant?
  
• What is the origin of emission of X-rays.
  
• Why the Rutherford's atomic model was rejected?
  
• What factors affect the strength of a bond?
  
• Define Born-Haber cycle and lattice energy.
  
• State first law of thermodynamics and Hess’s law.
  
• Define pH and pkw.

4. Attempt any SIX 4104lions. (6x2=12)

• Calculate Oxidation number of chromium in the following compounds.
  CrCl₃
  K₂CrO₄
  
• The radioactive decay is always first order reaction. Explain.
  
• A finely divided catalyst may prove more effective Give reason.
  
• Define common Ion effect with one example.
  
• Non-Ideal solutions do not obey Raoults Law, Why?
  
• Define molefraction and parts per million.
  
• What are colligative properties and why they are called so?
  
• What is meant by electromotive force (emf) of cell?
  
• Write down the functions of salt bridge.

SECTION –III

Attempt any THREE questions.

5.  (a) Define vapor  pressure. How is it measured by manometric method?
(b) Mg reacts with HCI to give hydrogen gas. What is the minimum volume of HCI solution (27% by weight) required to produce 16.1g of  H₂, the density of HCl solution is 1.14g /cm³ Mg +2HCl → MgCl₂ + H₂, At.wt. of Mg is 24 a.m.u

6. (a) Define hybridization and explain structure of water on its basis.
(b) Describe bomb calorimeter method for the determination of enthalpy of reaction.

7. (a) State Dalton's law of partial pressures. Write down its there applications also.
(b) Ruther fords atomic model is based on the scattering of α -particles from a thin gold foil. Describe it and explain the conclusion.

8. (a) Decribe the construction and working of standard hydrogen electrode.
(b) N₂(g) and H₂(g) combine to give NH₃(g) . The value of Kc in this reaction at 5000C is 6.0 x 10^-2. Calculate the value of K p for this reaction.

9. (a) How Raoult's law can be defined in three different ways? Also give their mathematical expressions.
(b) What are enzymes? Give their characteristics.

SECTION –IV: Attempt any THREE questions.

10. (a) The given solution contains 8 gms of a mixture of oxalic acid and sodium oxalate in 1dm³ . Determine the percentage of sodium oxalate. (Molecular mass of oxalic acid = 126)
(b) The given solution contains 6g of KMnO₄ dissolved per dm³. Determine the percentage purity of the sample. (Molecular mass of KMnO₄ = 158 )
(c) Determine the amount dissolved per dm³ of Iodine in the given sample of solution. (Molecular mass of Iodine=254)
(d) Prepare the pure crystals of benzoic acid from water by the process of crystallization.
(e) Separate and Identify lead and cadmium Ions in a mixture solution by paper chromatography.