Roll No: Federal Board HSSC-I ...

[Pages:7]A-PDF Watermark DEMO: Purchase from A- to remove the watermark

Roll No:

Answer Sheet No:

____________

Signature of Candidate: ___________ Signature of Invigilator: ____________

Federal Board HSSC-I Examination Chemistry Model Question Paper

SECTION ? A

Time allowed: 30 minutes

Marks: 17

Note: Section-A is compulsory and comprises pages 1-4. All parts of this section are to be answered on the question paper itself. It should be completed in the first 30 minutes and handed over to the Centre Superintendent. Deleting/overwriting is not allowed. Do not use lead pencil.

k Q.1 Encircle the correct option i.e. A / B / C / D / E. All parts carry equal marks.

i. According to VESPR model, the geometry of molecule having 5 bond pair in

outer most shell will be

lt.p A. Triangular

B. Square planner

C. Trigonal bipyramidal

D. Octahedral

E. Tetrahedral

ii. Geometry of molecule will be pyramidal, when number of electrons pairs in outer

most shell of central atom is

A. 3 bond pair, one lone pair

B. 2 bond pair, 2 lone pair

C. 4 bond pair, 1 lone pair

D. 1 lone pair, 3 bond pair

E. 1 bond pair, 4 lone pair

iii. Value and the units of gas constant R in SI system is

A. 0.0821 dm3 K-1 atm-1

B. 82.1cm3 atm K-1

u C. 8.31 Nm K-1 mol-1

D. 8.31 Cal K-1 mol-1

E. 8.314 L-1 mol K-1

iv. For a gas where volume and pressure are 1dm3 and 2atm respectively, what

should be its new volume, when pressure is increased to 6 atm at constant

s temperature?

A. 1/2dm3 C. 1/4dm3 E. 3/4dm3

B. 1/3dm3 D. 2/3dm3

e v. Which one is false for evaporation? A. surface phenomenon C. endothermic E. Spontaneous

B. continuous D. exothermic

Rvi. MgO and CsF have both atomic ratio 1:1 in their crystals, such property is

A. Polymorphism

B. Isomorphism

C. isotropy

D. allotropy

E. Anisotropy

Page 1 of 4

Turn Over

DO NOT WRITE ANYTHING HERE

vii. In which of the following equilibrium will Kc and Kp have the same value:

A. PCl5

PCl3 + Cl2

B. N2 + 3H2

2NH3

C. 2CO + O2

CO2

D. N2 + O2

2NO

E. 2SO2 + O2

2SO3

viii. In buffer solution, the concentration of acid is 10 times the concentration of salt

added, the pH of this solution is

k A. pKa + 1

B. pKa ? 1

C. pKa + 2

D. pKa ? 2

E. pKa + 10

ix. The unit of rate constant for 2nd order reaction is

lt.p A. mole.dm-3.sec

B. mole.dm3sec

C. mole.dm3.sec-1

D. mole-1.dm3.sec-1

E. mole2.dm3.sec-1

x. 5.85g of NaCl in 1 litre of water, the concentration of solution will be

A. 0.1M

B. 1m

C. 1M

D. 0.1m

E. 0.01M

xi Which of the following solutions will have highest boiling point:

A. 1 molal solution NaCl

B. 1 molal solution of Mg I2

C. 1 molal solution AlCl3

D. 1 Molar KCl

u E. 1 molal solution WCa

xii. Change in enthalpy of a system can be calculated by following relationship

A. = +

B. = -

s C.

= + 1

2

E. = +

D. = 2 -

xiii. In electrolytic solution conductance of electricity is due to movement of

A. Free electrons

B. Ions

C. molecules

D. Bonded electrons

eE. Solvent molecules

xiv. 43 + 52 4 + 62 If one mole of NH3 reacts with one mole of O2, then

A. One mole of NO is produced

B. One mole of H2O is produced

RC. All NH3 is consumed

D. All O2 is consumed

E. 0.8 mole NO is produced

Page 2 of 4

Turn Over

xv. The number of atoms present in a molecule determine its.

A. Molecularity

B. basicity

C. acidity

D. atomicity

E. Molality

xvi. Splitting of spectral lines when atom is subjected to magnetic field is called

A. Zeemans effect

B. Starks effect

C. Photo electric effect

D. Compton effect

E. Resonance effect

xvii. How many quantum numbers have been derived from Schrodinger wave

equation?

A. 01

B. 02

C. 03

D. 04

E. 05

k xviii.

Which of the following gas has the highest density under room conditions?

A. CO

B. N2

C. Ne

D. NH3

E. SF6

lt.p xix. Which one of the following compounds does not undergo hydrolysis?

A. CH3COONa

B. NaNO3

C. CuSO4

D. AlCl3

E. NH4Be

xx. The oxidation No. of Mn in K2MnO4 is A. 5 C. 3 E. 6

B. 4 D. 7

xxi. The SI unit for Eo (permittivity of vaccume) is:

u A.

C2J-1m-1

B.

C. C-2Jm

D.

E.

C2Jm-1

V2Jm-1 C Cal-1m-1

s xxii. The third line of Ballmer Sericre appears due to the transition of electron from:

A. n5 to n2

B. n4 to n2

C. n5 to n1

D. n4 to n1

E. n3 to n1

Re xxiii.

The value shell electronic configuration of 13Al is 3S2 3P1 which set of quantum

number is permissible for 3P electron.

A. n = 3 l = 0 m = 0 s = +?

B. n = 3 l = 1 m = 1 s = -?

C. n = 4 l = 2 m = 2 s = +?

D. n = 3 l = 2 m = 1 s = +?

E. n = 4 l = 3 m = 2 s = +?

Page 3 of 4

Turn Over

xxiv.

The electronic configuration of O2+1 is [KK(2s)2 (2px)2 (2py)2 (2p3)2 (2py)1]. The bond order of O2+1 is:

A. 2

B. 1.5

C. 2.5

D. 3

E. 1

xxv. The unit for Van der Waals constant "a" is:

A. J cm6 mole-2

B. atm dm6 mole-2

C. alm2 dm3 mole-1 E. atm dm3 mole-2

D. cal2 dm6 mole-2

xxvi.

The total pressure of two moles of N2 and five moles of Hydrogen in a container

is 15 atm. The partial pressure of H2 in the container is:

A. 10.1

B. 4.3

C. 10.7

D. 4.8

E. 15.1

k xxvii. The coordination number of Cl-1 in CsCl is:

A. 4

B. 6

C. 8

D. 2

E. 10

lt.p xxviii. If three moles of SO2 are oxidized to SO3, then how many moles of oxygen

molecules are required?

A. 1.0

B. 1.5

C. 2.5

D. 0.5

E. 2.0

u xxix.

A Compound "A" is dissolved in Benzen, the vapour pressure of Benzen is

lowered from 98.6 to 86.7 torr. The mole fraction of compound "A" is:

A. 0.21

B. 0.25

C. 0.30

D. 0.12

E. 0.22

xxx. The Kb of water is 0.52?cm-1, the boiling point of 2 Molal solution of glucose in

water is:

s A. 101.08?C

B. 100.04?C

C. 104.2?C

D. 101.04?C

E. 102.04?C

Re For Examiners use only

____________________ Q. No.1: Total Marks: 17

Marks Obtained:

Page 4 of 4

Federal Board HSSC-I Examination Chemistry Model Question Paper

Time allowed: 2.30 hours

Total Marks: 68

Note: Sections ,,B ,,C and ,,D comprise pages 1-2 and questions therein are to be answered on

Q.2 Q.3

the separately provided Answer Book. Use supplementary answer sheet i.e., sheet B if required. Write your answers neatly and legibly.

SECTION ? B (Marks 21)

(From Chapter 1 ? 6)

Attempt any SEVEN parts. All parts carry equal marks.

(7 3 = 21)

i.

Calculate the number of +ve and ?ve ions dispersed when 2.35 X 10 22 molecules

k of H2SO4 were dissolved in solution.

ii. Why is theoretical yield is always greater than actual yield?

iii. What is the origin of positive and X-rays?

iv. Calculate the frequency of limiting line in Balmer series.

v. Explain hybridization in BF3 , also draw its structure.

lt.p vi. Energy of sigma 2px in O2 molecule is lower than Pi 2py and 2pz, however this

order is reversed in N2. Justify. vii. Derive the expression for pressure correction (P=an2/ v2) in vander waals

equation.

viii. Equal volumes of HCl and SO2 are confined in a porous container, what would be

the comparative rates of diffusion of these gases through the porous wall. Molar

Mass of HCl: 36.5gm/mol and SO2 64gm/mol

ix. Why the London dispersion forces increases by increasing the atomic and

molecular size.

x. Differentiate b/w Isomorphism and Polymorphism with example.

u SECTION ? C (Marks 21) (From Chapter 7 ? 12)

Attempt any SEVEN parts. All parts carry equal marks.

(7 3 = 21)

s i.

Following reaction was studied at 250C, Calculate its Kp and Kc

2NO (g) + Cl2 (g)

2NOCl (g)

The partial pressures at equilibrium were found to be P NOCl= 1.2atm, PNO=5.0x 103 atm and PCl2=3x 10-1 atm

ii. How does equilibrium constant explain the extent of chemical reaction?

e iii. Prove the following relationship for conjugate acid-base pair.

Ka x Kb= Kw

iv. Define hydrolysis. Justify that the aqueous solution of CuSO4 is acidic and

CH3COONa is basic?

v. What is energy of activation? Also describe the role of catalyst in a chemical

Rreaction.

vi. Rate of reaction gets increased by temperature. Describe on molecular level using

Boltzman curve.

Page 1 of 2

Turn Over

vii. Calculate the molality of 15% (w/w) of Urea (NH2)2CO solution.

viii. Why the addition of non-volatile, non-electrolyte solute increases the boiling

point.

ix. Balance the following equation by half reaction method in acidic media.

S2O8-2 + Cr+3

SO4-2 + Cr2O7-2

x. What is first law of thermodynamics? Drive the expression for the enthalpy

change of the chemical system at constant pressure.

SECTION ? D (Marks 26)

Note: Attempt any TWO questions. All questions carry equal marks. (2 13 = 26)

(Q.4. From chapters 1 to 6)

Q.4 a. Derive Bohrs equation for the radius of nth orbit of electron in Hydrogen atom.

Also calculate radius of of Li +2 ion.

(7)

k b . Draw molecular orbital diagrams for O2, O2 -2 and O2 +2 and explain their

paramagnetic or diamagnetic behavior.

(6)

(Question 5 From Chapters 7 to 12)

lt.p Q.5 a. Describe the quantitative aspect of freezing point depression graphically. (6)

b. What is Standard Hydrogen Electrode? How can it help to find electrode potential

of zinc?

(7)

(Question 6: Part a from chapters 1 to 6 Part b From Chapters 7 to 12)

Q.6 a. Compare the properties of covalent and Ionic solids in tabular form.

(6)

b. Define Raoults law. How can it explains the solubility of completely miscible

system of two volatile components in one another.

(7)

Resu ____________________

Page 2 of 2

Result.pk

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download