FAISALABAD BOARD 2012
CHEMISTRY
PART-I
Time: 20 Min.
(Objective Part)
Marks: 17
Note: Four answer are given against each question in columns A, B, C and D. Select the right answer and on the separate Answer Sheet, fill the circle A, B, C or D with pen or marker in front of that question number.

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

(a) 7f
(b) 7S
(c) 7P
(d) 7d

• Splitting of spectral lines when atoms are subjected to strong electric field is called:

(a) Zeeman effect
(b) Stark effect
(c) Photoelectric effect
(d) Compton effect

• Which is a pseudo solid?

(a) CaF₂
(b) NaCl
(c) Glass
(d) All

• When water freezes at 0°C , its density decreases due to:

(a) Cubic structure of ice
(b) Empty spaces present in the structure of ice
(c) Change of bond length
(d) Change of bond angles

• A real gas objeying Vander Waals equation will resemble ideal gas if:

(a) Both "a" and "b" are large
(b) both "a" and "b" are small
(c) "a" is small and "b" is large
(d) "a" is large and "b" is small

• If absolute temperature of a gas is doubled and the pressure is reduced to one half, the volume of the gas will:

(a) Remain uncharged
(b) Increase four times
(c) Reduce to 1/4
(d) Be doubled

• The comparative rates at which the solute move in paper chromatography depend on:

(a) Size of paper
(b) Temperature of the experiment
(c) R_f value of solute
(d) Size of the chromate-graphic tank used

• The mass of one mole of electron is:

(a) 1.008mg
(b) 0.5mg
(c) 0.184mg
(d) 1.673mg

• In zero order reaction, the rate is independent of:

(a) Temperature of reaction
(b) Concentration of reactants
(c) Concentration of products
(d) None of these

• If the salt bridge is not used between two half cells, then voltage.

(a) Decrease rapidly
(b) Decrease slowly
(c) Does not change
(d) Drops to zero

• Stronger the oxidizing agent, greater is the:

(a) Oxidation potential
(b) Redox potential
(c) Reduction potential
(d) E.M.F. of cell

• A solution of glucose is 10% W/V. The volume in which 1 gram mole of it is dissolved will be:

(a) 1dm³
(b) 1.8dm³
(c) 200cm³
(d) 900cm³

• The solubility product of AgCl is 2.0 x 10¹⁰ mol²dm^-6.The maximum concentration of Ag⁺ ions in the solution is:

(a) 2.0 x 10^-10 mol dm^-3
(b) 1.41x 10^-5 mol dm^-3
(c) 1.0 x 10^-10mol dm^-3
(d) 4.0 x 10^-2 mol dm^-3

• The change in the heat energy of a chemical reaction at constant temperature and pressure is called:

(a) Enthalpy change
(b) Heat of sublimation
(c) Bond energy
(d) Internal energy change

• A limiting reactant is the one which:

(a) Is taken in lesser quantity in grams as compared to other reactants
(b) Is taken in lesser quantity in volume as compared to other reactants
(c) Gives the maximum amount of the product which is required
(d) Gives the minimum amount of the product under consideration

• A limiting reactnat is the one which:

(a) O²⁺₂
(b) O^2-₂ 
(c) B₂ 
(d) F₂

• Which hydrogen halides have the highest percentage of ionic characters?

(a) HCL
(b) HBr
(c) HF
(d) HI

Time: 2:40 Hours
(Subjective Part)
Marks: 68
SECTION-I:

Q.2.Write short answer any Eight Parts. 16

• Differentiate between empirical and molecular formula.
• Why the experimental yield is always less than theoretical yield?
• No individual neon atom in the sample of the element has a mass of 20.18 a.m.u. Discuss.
• Explain the process of sublimation.
• Concentrated HCl and KMnO₄ solutions cannot be filtered by using filter paper. Discuss.
• Define Boyle's law and give its mathematical expression.
• Convert - 40°C of F°.
• State what is natural and artificial plasma?
• Why gases show non ideal behaviour at low temperature and high pressure?
• Define boiling point.
• Why do we feel cooling effect after taking bath?
• Metals are malleable and ductile. Justify.

 Q.3.Write short answer any Eight Parts. 16

•  Give two defects of Bohr's atomic model.
• Define Moseley's law. Give its mathematical equations.
• State Heisenberg's uncertainty principle.
• Define ionization energy. How does it vary in the periodic table?
• Define bond length and bond energy.
• Define system and surrounding. Give one example of each.
• Why is it necessary to mention the physical states of reactants and products in a thernio chemical reaction?
• What is lattice energy? Give one example.
• Give two definitions of Raoult's law.
• Define solubility curve. Name it two types.
• Give two functions of salt bridge.
• How is rate of reaction in fluenced by surface area?

 Q.4.Write short answer any Six Parts.12

• Why abnormality of bond length and bond strength in HI is less prominent than that of HCl?
• Write short note on atomic radii and ionic radii. Give examples.
• What is the effect of common ions on solubility?
• How can you determine K_sp from solubility?
• Define buffer capacity.
• What is the effect of catalyst on equilibrium constant (Kc)?
• Define electrode potential. Give example.
• Define electrolytic conduction. Give example.
• Define energy of activation.

SECTION-II

 Q.5.(a) Define and explain the concept of Mole and Avogadro's number with examples.(04)
(b) What are intermolecular forces? Write the names of different types of their forces and explain instantaneous dipole-induced dipole forces. (04)

Q.6.(a) Define bond energy and explain the various parameters which determine is strength. (04)
(b) When 2.00 moles of H₂ and 1.00 mole of O₂ at 100° C and 1 torr pressure react to produce 2.00 moles of gaseous water, 484.5KJ of energy is evolved. What are the values of (a) êH and (b) êE for the production of one mole of H₂O (g)? (04)

Q.7.(a) A sample of nitrogen gas is enclosed in a vessel of volume 380cm³ at 120°C and pressure of 101325Nm^-2. This gas in transferred to a 10 dm³ flask and cooled to 27° C. Calculate the pressure in Nm^-2 exerted by the gas at 27° C.(04)
(b) Dicsuss properties of cathode rays. (04)

Q.8.(a) Prove that: pK_a + pK_b = pK_w,(04)
(b).Explain "LEAD ACCUMULATOR" with charging and discharging. (04)

Q.9.(a) Explain the fractional distillation. Justify the two curves when composition is plotted against boiling point of the solution. (04)(b).Discuss the factors which influence the rates of chemical reactions.(04)