Class 1ST YEAR Federal Board 2009
Paper:Chemistry (Objective Type) Time Allowed: Max.Marks:
Note:Use this paper to write the answers to the objective questions.No marks will be awarded for cutting,over-writing or using a pencil.This paper must be tagged with the answer-book.

1- Insert the correct option.
(i) Dipole moment is the measure of palarity. Which one of the following molecules in polar ?
(A) CCL 3 (B) BF 3 (C) CF 4 (D) NF 3
(ii) When two ice cubes are pressed over each other,they unite to form one cube. Which force holds them together ?
(A) Covalent bond (B) Electrostatic interaction
(C) Co-ordinate covalent bond (D) Hydrogen bonding
(iii) Which one of the following substance will conduct electric current without a chemical change ?
(A) An aqueous (B) An electrolyte
(C) Solid sodium chloride (D) A liquid metal
(iv) The mutual solubility of conjugate solutions is affected by.
(A) Pressure (B) Volume
(C) Mass (D)Tempreature
(v) Which one of the following is not the property of an ideal solution ?
(A) ^H sol=0 (B) ObeysRault's law (C) ^V - 0
(D) Attractive forces are some irrespective of nature of molecules.
(vi) In hydrogen electrode which standard hydrogen electrode (SHE) condition is relevant:
(A) 1.00 M HCL solution. (B) H2 gas at 1 atm pressure
(C) Plantinum electrode. (D) All of the above
(vii) Which one of the following is a property of a solution of dry hydrogen chloride in dry methyl benzene ?
(A) It has pH less than 7.
(B) It is a non conductor of electricity.
(C) It reacts with magnesium to give hydrogen
(D) It reacts with dry CuO on warming to give blue solution
(viii) Which reaction will always be exothermic ?
(A) oxidation (B) Dehydrogenation
(C) Sublimation (D) Neutralization reaction.
(ix) An experimentally determined quantity is called:
(A) Oder of reaction (B) Oder of action
(C) Rate of reaction (D) Non of these
(x) The pH of egg at 25 C is:
(A) 3.9 (B) 6.7 (C) 7.5 (D) 7.8
(xi) A solution of glucose is 10%. The volume in which one gram mole of it dissolves will be.
(A) 1 dm 3 (B) 1.8dm 3 (C) 200 cm 3 (D) 900 cm 3
(xii) Which type of a cell is much important in a space vehicle ?
(A) Electrical energy is produced from consumption of metallic electrodes.
(B) Electrical energy is produced from the reaction of liquid materials.
(C) Electrical energy is produced from the reactions of solid materials.
(D) Electrical energy is produced from the reactions of gaseous material.
(xiii) When NaOH solution reacts with Aluminium in different physical states most rapid reaction occurs with.
(A) Aluminium powder (B) Cubes of Aluminium
(C) Aluminium powder (D) Alloys of Aluminium
(xiv) The unit of mole fraction is:
(A) mole dm 3 (B) moles kg-1
(C) gm dm-3 (D) None of these
(xv) If temperature of water increases from 25 C to 35 C. What will happen ?
(A) The water will become acidic due to increases in concentration of H + as compared to OH-ions
(B) The water will become basic due to increase in concentration of OH as compared to H + ions.
(C) The water will remain neutral due to no change in concentration of H + ions OH - ions.
(D) The concentration of both H + and OH - increases equally and water will remain neutral.
(xvi) Which theory explain that pairs of electrons around the central atom lie at maximum repulsion ?
(A) VSE PR theory (B) VB theory
(C) MO theory (D) None of these
(xvii) The partial pressure of water vapours in gasses is called:
(A) Surface tension (B) Aqueous tension
(C) Tension (D) None of these
2. Attempt any 14 parts (14 x 3 =42)

(i) Liquid air is separated roughly into N2 78%, O2 21% and Argon 1% which of three:
(a) To fill a diver's cylinder
(b) To flush out an empty fuel tank.
(c) To put in filament light bulb.
(ii) List the raw materials for the industrail production of ammonia under what condition does the reaction go best ?
(a) Electrical energy is produced from the reactions of gaseous material.
(iii) Calcium nitrate is a soluble salt. it ionizes in water to produce calcium and nitrate ion.
Calculate the molarities of positive and negative ions produced by dissociation of 9g dm-3 calcium nitrate.
(Ca = 40, N = 14, O = 16)
(iv) The buffer capacity of a solution is the capability of a buffer to resist the change of pH.
(a) Write henderson equation.
(b) Explain using equation why an aqueous mixture of acetic acid (Na + A-) can act as a buffer solution on the addition of an acid or an alkali.
(v) Molar mass is atomic mass, molecular mass formula mass or ionic mass of the substance expressed in grams. How many grams are there in each of the following.
(a) 3 moles of sodium Na.
(b) 2 moles of sodium chloride NaCl.
(c) 0.01 moles of calcium carbonate. (At mss oxygen = 16, sodium = 23, chlorine = 35.5, ca = 40, C = 12)
(vi) Liquid crystals can diffract light.
(a) Why liquid crystals act as temperature sensors ?
(b) Why liquid crystals look coloured ?
(vii) Transition temprature is that temperature at which two crystalline forms of the same substance can co-exist in equilibrium with each other.
(a) What is allotropy ? Give allotropic forms of sulphur and carbon.
(b) Tin posses transition temperature. Give value of transition tempreature of tin and allotropic forms of tin.
(viii) Chromatography is derived from two words ''Chroamtos'' means ''Colours'' and graphy means ''Writing'' or '' drawing''.
(a) What is the principle of chromatography ? Write down in two lines.
(b) The chromatogram given below shows the distance traveled by the solvant and the two dyes A and B. Calculate the R value of dye A and dye B.
(ix) One mole any gas has the same number of molecules. Na if equal number of molecules correspond to equal volumes at S.T.P (Avogadro's hypothesis) then one mole of one gas has the same volume has the value 22.414 L (dm3).How many litres of oxygen, at standard conditions, can be obtained from 100g of potassium chlorate ?
2KClO3--------->2KCl + SO2
(solid) (Gas)
(x) pressure is the force acting normally on a undit area of surface. A standard atmosphere (1 atm) is defined as exactly 101325 Pa. it is proximately equal to the average pressure of the atmosphere at sea level.
How high a column of air would be necessary to cause a barometer to read 76 cm of mercury, if the atmosphere where of uniform density 1.2 Kg/m3 ? The density of mercury is 13.6x 10 3 Kg/m3
(xi) A metal object to be plated is connected as the cathode in a cell containig silver anode and silver nitrate solution.Give a lump of silver. a solution of silver nitrate and some knives and folks.
How would you silver plate the cutlery ?
(xii) Consider the following general electrolytic cell.
(a) At which electrode does oxidation occur ?
(b) At which electrode does element M form ?
(c) At which electrode are electrons deing released by ion ?
(xiii) Stoichiometry is a branch which tells us the quantitative relationship between rreactants and products in a balanced chemical it in the acidic medium. Show all steps.
Cr 2 O 2 + Fe 2 + --------> Cr 3 + Fe 3+(Acidic medium)
(xiv) Order of reaction is the number of reacting molecules whose concentrations alter as a result of chemical change.
(a) What is zero order reactions ?
(b) Give the relation between half life and order of reaction.
(xv) Ammonia and fluorine react to produce dinitrogen tetra fluoride according to
the following reaction.
2NH 3 + 5F 2 ------> N 2 F 4 + 6 HF
(g) (g) (g) (g) If 4.00g ammonia and 14.0g of fluorine are allowed to react.
(a) How many grams of dinitrogen tetra fluoride are produced ?
(b) Name the reactant, which is in excess also calculate its volume at STP which is left unreacted.
(xvi) For the distribution of iodine between two immisible solvents (H2O and CC14) iodine reacts with iodide ion to form triodide ion in areversible reaction,
(a) Write the reaction for this purpose.
(b) Name and state the law followed.
(c) Write the distribution co-efficient for this reaction.
(xvii) The following sets of quantum numbers are not allowed. For each ste why ?
(a) n = 3 l = 3 m = 0 s = -1/2
(b) n = 2 l = 1 m = -1, s = -1
(c) n = 3 l = 1 m = -2 s = -1/2
(xviii) Sodium atom imports yellow colour when excited in a flame the wave length of this colour in emission spectrum is 589.0nm.
(a) What is the frequency of this radiation ?
(b) What is the energy of this radiation per photon and per mole of photon ?
(ix) Dipole moment is the produce of the electric charge and distance between the position and Negative centres
(a) Write the formula and unit of dipole moment .
(b) Explain the polarity of H2O molecule .
Attempt any TWO questions. (2 x 13 = 26)
(3.a) Product of molar concentration of two ions at equilibrium is Ksp.
(i) Define solubility product.
(ii) Derive the soulbility product expression for sparingly soluble compounds.
AgCl, Ag 2 CrO4 and PbCl2
(b.i) What is ment by lattice energy ?
(ii) Lattice energy of compounds cannot be measured directly by any method. State indirect method used for its measurement.
(iii) Draw stepwise flow sheet diagram for measurement of ^ H for potassium chloride KCl)
(c) In the equilibrium.What is the effect on the position of equilibrium mixture ?
(i) Temperature is incerases. (ii) Pressure is decreased
(iii) Any amount of nitrogen is added to the equilibrium mixture.
(4.a) The diagram below shows a galvanic cell for the measurement of electrode potential.
(i) Write the reaction on each electrode.
(ii) How can you calculate the standard electrode potential of copper ?
(iii) Explain briefly the working of this cell.
(iv) What is the function of porous partition ?
(b) Bohr presented an alternative modle of hydrogen atom and removed defects in rutherford's atomic modle.
(i) Give defects in Rutherford atomic mode.
(ii) Bohr's equation for the radius of nth orbit of electron in hydrogen atom is r n =E H2n2e2 m
How much does the radius of the orbit increases, when the electron moves from n = 1 ton = 2 ?
(iii) What is the distance traveled by the electron when it does n = 2 to n = 3 and n = 9 to n= 10 ?
(5.a) When a compressed gas is allowed to expand into a region of low pressure.
(i) What is the effect of low pressure on that gas name that effect ?
(ii) Is it necessary that temperature must decrease after applying the pressure for liquification
(iii) Gases show non ideal behaviour under what conditions. Explain this with the help of graph.
(b) The relative lowering of vapour pressure is equal to the mole fraction of solute.
(i) State and explain Rault's law.
(ii) Derive a relationship between mole fractions of two volatile compounds and their vapour pressure