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Guess
Papers
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Class 1st Year) |
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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. |
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