SAHIWAL BOARD 2017
PAPER CHEMISTRY PART-1
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.

• Which of the following has coordinate covalent bond?
  
  (A) NH₄Cl
  (B) NaCl
  (C) HCl
  (D) AlCl₃


• For given process, the heat changes at constant pressure (qp) and at constant volume (qv) are related to each other as
  
  (A) qp=qv
  (B) qp<qv
  (C) qp>qv
  (D) None of these


• pH of blood is:-
  
  (A) 6.35
  (B) 7.35
  (C) 8.35
  (D) 9.35


• Solubility product of AgCI is 2.0 x10^-10 mol1 dm⁶.The maximum concentration of Ag+ ions in solution is
  
  (A) 2.0 x 10^-10 mo1/ dm³
  (B) 1.41 x 10^-5 mo1/ dm ³
  (C) 1.0 x 10^-20 mo1/ dm ³
  (D) 4.0 x 10^-20 mo1/ dm³


• A solution of glucose is 10%, the volume in which 1g moles of it is dissolved will be.
  
  (A) 1dm³
  (B) 1.8dm³
  (C) 200cm³
  (D) 900cm³


• Oxidation number of 'Cr' in K₂CrO₄ is
  
  (A) +2
  (B) +4
  (C) +6
  (D) +8


• In zero order reaction, the rate is independent of
  
  (A) Temperature of reaction
  (B) Concentration of reaction
  (C) Concentration of products
  (D) Pressure of reaction


• Cadmium has isotopes
  
  (A) 3
  (B) 4
  (C) 5
  (D) 6


• The volume occupied by 1.4 g of 815 at S.T.P is
  
  (A) 22.4 dm³
  (B) 2.24 dm³
  (C) 1.12 dm³
  (D) 112cm³


• Compound which undergo sublimation is
  
  (A) KMnO₄
  (B) CaCl₃
  (C) NH₄Cl
  (D) Na₂CO₃


• Which of the following will have highest rate of diffusion?
  
  (A) O₂
  (B) CO₂
  (C) NH₃
  (D) SO₂


• The deviation of gas from ideal behavior is maximum at
  
  (A) -10 °C and 5 atm
  (B) -10 °C and 2 atm
  (C) 100 °C and 2 atm
  (D) 0°C and 2 atm


• Transition temperature of KNO₃ is
  
  (A) 13.2°C
  (B) 95.5 °C
  (C) 128°C
  (D) 32.2°C


• Vapour pressure of liquid depends upon
  
  (A) Amount of liquid
  (B) Surface area
  (C) Temperature
  (D) Size of container


• When 5d orbital is completed then entering electron goes into
  
  (A) 6s
  (B) 6p
  (C) 6d
  (D) 6f


• Quantum number values for 2p orbitals are
  
  (A) n=2.1 = 1
  (B) n=1,1=2
  (C) n=1./ = 0
  (D) n=2,1=0


• Which of the following has unpaired electrons?
  
  (A) O₂²⁺
  (B) O₂³⁺
  (C) N₂^2-
  (D) F_2-

SAHIWAL BOARD 2017
PAPER CHEMISTRY PART-1
Time: 3:10 Hours (Subjective Part)
Marks: 83
Section-I

Q.2 Write short answers to any EIGHT (8) questions.

1. What is the function of magnetic field in mass spectrometer?
   
2. Differentiate between empirical and molecular formula.
   
3. Mg atom is twice heavier than that of a carbon atom. How?
   
4. Differentiate between qualitative and quantitative analysis.
   
5. How saturated solution for crystallization can be prepared?
   
6. Liquids are less common than solids and gases. Why?
   
7. Convert 37°C into F° scale.
   
8. Define diffusion and effusion.
   
9. What is the effect of temperature change on the direction of the reaction?
   
10. N_2(g) + 3H_2(g)⇔ NH_3(g) + heat
    
11. Define common ion effect. Give its one use.
    
12. What is meant by ionization constant of acids?
    
13. How undesirable colors of crystals can be removed?

Q.3 Write short answers to any EIGHT (8) questions.

1. What is polymorphism? Give one example.
   
2. What type of intermolecular forces will dominate in the following liquid?
   (a) CH₃COCH₃ (propanone)
   (b) C₈H1₈ (Octane)
   
3. Why ionic solids do not conduct electricity.
   
4. Iodine dissolves readily in tetra chloromethane. Justify.
   
5. Write down two postulates of Plank's Quantum Theory of radiations.
   
6. Differentiate between continuous and line spectrum.
   
7. State Pauli's Exclusion Principle.
   
8. Write electronic configuration of elements having atomic number 15 and 29.
   
9. Define mole-fraction; also give its mathematical form.
   
10. Why heat of hydration of Li+ is greater than that of Cs+?
    
11. Calculate the oxidation state of underlined element,
    (a) H₃PO₃
    (b) Ca(ClO₃)₂
    
12. How relative chemical reactivity of metals is studied with the help of electrochemical series.

Q.4 Write short answers to any SIX (6) questions.

1. Define ionization energy. How does it vary in Periodic Table?
   
2. Differentiate between polar covalent bond and nonpolar covalent bond
   
3. What is bond order? Determine the bond order of Helium molecule.
   
4. Define coordinate covalent bond. Give one example.
   
5. Describe state function with an example.
   
6. What are spontaneous reactions? Give an example.
   
7. What is heterogeneous catalysis? Give one example.
   
8. Differentiate between instantaneous and average rate of reaction.
   
9. Define half-life period. How is it related to order of reaction?

Section-II

NOTE: Attempt any THREE questions.
Q. 5 (a) Serotenin is a compound that conducts nerve impulses in brain and muscles. It contains 68.2%C, 6.86% H, 15.09% N and 9.08% O. What is its molecular formula? (Molar mass of Serotenin = 176gmol^-1
(b) Write four properties of metallic crystals.

Q. 6 (a) State and explain Dalton's Law of Partial pressures. Derive an expression for calculating Partial pressure of a gas.
(b) What is Atomic spectrum? Explain its types.

Q. 7 (a) Calculate the bond order of O₂ molecule by making energy level diagram. Also show that it is paramagnetic.
(b) What is the first law of thermodynamics? Dive its Mathematical form.

Q. 8 (a) Ca(OH)₂ is a sparingly soluble compound. Its solubility product is 6.5 x 10^-6. Calculate the solubility of Ca(OH)₂.
(b) Explain lead accumulator battery and its discharging process.

Q. 9 (a) Describe Landsberger's method for measurement of boiling point elevation.
(b) Write down four important characters of catalysts.