RAWALPINDI BOARD 2015
PAPER CHEMISTRY PART-I
(Objective Part)
Time: 20 Minutes       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 cathodic reaction in the electrolysis of dil H₂SO₄ with Pt electrode is.

A. reduction
B.
C.
D.

• The rate of reaction:

A. decreases as the reaction proceeds
B.
C.
D.

• Isotopes differ in

A. properties which depend upon mass
B.
C.
D.

• The mass of one mole of electron is

A. 0.55mg
B.
C.
D.

• Solvent extraction is an equilibrium process and it is controlled by

A. Distribution law
B.
C.
D.

• Pressure remaining constant, at which temperature the volume of a gas will become twice of what is at 0°C

A. 546K
B.
C.
D.

• The molar volume of CO₂ is maximum at

A. 127°C and 1 atm
B.
C.
D.

• Acetone and chloroform are soluble in each other due to.  

A. Intermolecular H-bonding
B.
C.
D.

• Ionic solids are characterized by

A. Solubility in polar solvents
B.
C.
D.

• Quantum number values for 2P orbital are

A. n=2, =1
B.
C.
D.

• When 6d orbital is complete, the entering electron goes into

A. 7p
B.
C.
D.

• The number of bonds in nitrogen molecule is

A. One σ and two π
B.
C.
D.

• Which of the following molecules has zero dipole-moment?

A. BF₃
B.
C.
D.

• Calorie is equivalent to

A. 4.184J
B.
C.
D.

• The pH of 10-3 mol dm-3 of an aqueous solution of H₂SO₄ is

A. 2.7
B.
C.
D.

• For which system does the equilibrium constant, kc has units of (concentration)

A. 2NO₂⇔N₂O₄
B.
C.
D.

• Molarity of pure water is

A. 55.5
B.
C.
D.

Inter (Part-I) Rawalpindi Board 2015
Chemistry
Part I (Subjective)
Time Allowed: 3.10 Hours 
Max. Marks: 83

SECTION-I

2. Attempt any EIGHT short questions.

• Molecular formula is a multiple of empirical formula, explain with example.
• Write four characteristics of a solvent selected for crystallization of a compound.
• Write down the postulates of kinetic molecular theory responsible for the deviation of gases from ideal behavior.
• How does the change of pressure shift the equilibrium position in the synthesis of ammonia?
• Calculate the number of atoms in 0.1g of sodium.
• Differentiate between actual yield and theoretical yield.
• What is solvent extraction? Give its importance.
• Write down the quantitative definition of Charles law.
• Define state function and give two examples.
• Draw a labeled diagram of bomb calorimeter.
• Define pH and give the pH of milk and eggs.
• How buffer solutions are prepared.

3. Attempt any EIGHT short questions.

• The radius of an atom cannot be determined precisely Give reasons.
• Differentiate between polar and non-polar covalent bonds with examples.
• What are dipole-induced dipole forces?
• What do you mean by cleavage and cleavage planes?
• What is transition temperature? Give examples.
• What is vacuum distillation? Give its advantages.
• State Heisenberb's uncertainty principle.
• State Pauli's exclusion principle.
• What is stark effect?
• What happens when a neutron decays?
• How does electron affinity vary in periodic table?
• Why second I.P of an element is always greater than First I.P?

4. Attempt any SIX short questions.

• How do you justify that freezing points are depressed due to the presence of solutes?
• Calculate oxidation number of chromium in
  a) K₂Cr₂O₇
  b) K₂CrO₄
• Differentiate between instantaneous rate and average rate of a reaction.
• What is meant, by critical solution temperature?
• Define molarity of a solution. Give its equation.
• What is meant by standard hydrogen electrode?
• A salt bridge Maintains the electrical neutrality in cell. Justify.
• What do you mean by half life period?
• Define homogeneous catalysis and give an example.
  

SECTION-II

Attempt any THREE questions.. (8 X 3 = 24)

Question #5 
a) What are ionic solids? Give their properties.
b) Calculate the number of grams of K₂SO₄ and water produced when 14g KOH are reacted with excess of H₂SO₄. Also calculate the number of molecules of water produced. (At mass K = 39, S = 32)

Question #6 
a) What is Graham's law of diffusion? Also give its experimental verification.
b) Write the postulates of Bohr's atomic model.

Question #7 
a) Give salient features of VSEPR theory.
b) Stale and explain the first law of thermodynamics?

Question #8
a) Define the order of a reaction and give one example of first, second and third order reaction each.
b) Calculate the pH of a buffer solution in which 0.11 molar CH₃COONa and 0.09 molar acetic acid solutions are present. K_a For CH₃C00H is 1.85x 10⁵

Question #9
a) What is molal boiling point constant? How we can determine the molar mass of an unknown solid by elevation in boiling point method?
b) What is a galvanic cell? Give composition and working of galvanic cell.

SECTION –III:

Attempt any THREE Parts.

a) Purify the given sample of common salt obtained from Khewra mines by passing HCI gas through common ion effect.
b) Separate and identify Pb⁺² and Cd⁺² ions in a mixture by paper chromatography and also calculate R_f values.
c) The given solution contains 5g NaOH dissolved per dm³. Find out the percentage purity of the sample. (Molor mass pf NaOh=40)
d) The given mixture contains 35g FeSO₄ and (NH₄)₂SO₄ dissolved per dm³.Calculate the percentage composition of mixture. (Molor mass of FeSO₄. 7H₂O=278)
e) The given solution contains 24.8g Na₂S₂O₃. xH₂O dissolved per dm³. Find out the value of x. (molor mass of Na₂S₂O₃. xH₂O =158+18x)