H.S.C. Board Practice Question Paper Set A
Date: Sub.:
Chemistry (55) Seat Number:
Time: 3Hr.
(Physical
and Inorganic Chemistry) Marks: 70
Section I
Q. 1. Select and
write the most appropriate answer from the given alternatives for each sub
question. [07]
(i)The major binding
force in silicon is
(a) ionic bond (b) covalent bond
(c) dipole-dipole attraction (d)
induced dipole-dipole attraction
(ii) Lowering of
vapour pressure of solution
a) is a
property of solute b) is a
property of solute as well as solvent
c) is a
property of solvent d) is a
colligative property
(iii) For a chemical
reaction ΔS = - 0.035KJ/K and ΔH= -20KJ. At what temperature does the reaction
turn non-spontaneous?
(a) 5.14K (b) 57.14K (c) 571.4K (d) 5714.0 K
(iv) The following
reaction occurs in a galvanic cell
2Cu+ → Cu2+ + CuIf E°Cu+,Cu2+
= +0.16V and E°Cu+ |Cu = 0.52V, the standard cell potential will be
(a)0.68V (b)
0.36V (c) -0.36V (d)-0.68V
(v) A reaction is
first order with respect to reactantA and second order with respect to reactant
B.
The rate law
for the reaction is given by
(a) rate = k
[A][B]2 (b) rate =
[A][B]2
(c) rate = k [A]2[B]
(d) rate = k [A]0[B]2
(vi)The ores that are concentrated by
flotation method are:
(a) Carbonates (b) Sulphides (c) Oxides (d) Phosphates
(vii)PCl5 exists but NCl5 does
not due to
(a) Inertness of N2 (b) NCl5 is unstable
(c) Larger size of N
(d) Non-availability of vacant
d-atomic orbitals
Q. 2. Answer any
SIX of the following. [12]
(i) Distinguish between crystalline solids and
amorphous solids.
(ii) Marine life
like fish prefers to stay at lower level in water. Explain.
(iii) Prove that, ΔH
= ΔU + ΔnRT.
(iv) State
Kohlrausch's law and write mathematical expression of molar conductivity of the
given solution at infinite dilution.
(v) Define half
life of a reaction. Derive the relationship between half life and rate constant
for a first order reaction.
(vi) Describe
magnetic separation process.
(vii) What is the reaction of the following with ammonia:
(i) Cl2 (ii) Na.
(viii) State the first
law of thermodynamics indifferent ways.
Q.3. Answer any
THREE of the following. [09]
(i)Copper
crystallises into a FCC structure and the unit cell has length of edge 3.61 x
10-8cm. Calculate the density of copper. Atomic mass of copper is
63.5gm mol-1.
(ii) Calculate mole
fractions, molality and molarity of HNO3 in a solution containing
12.2% HNO3.
(Given: density
of HNO3 = 1.038 gm cm-3, H= 1, N= 14, O= 16).
(iii) Calculate the maximum work when 24 gm of oxygen are expanded isothermally and reversibly from a
pressure of 1.6 x 105 Pa to 100 kPa at 298 K.
(iv) What is reaction of the following with ammonia?
(a) Cu2+(aq) (b) Zn2+(aq) (c) Ag+(aq)?
Q. 4. Answer any ONE
of the following.
[07]
(i) (a) Explain Schottky
defect.
(b) (1) Osmosis
(2) Osmotic pressure.
(c) In acidic solution, sucrose is converted
to a mixture of glucose and fructose in pseudo
first order reaction. It has been
found that the concentration of sucrose decreased
from 20 m mol L-1 to 8 m
mol L-1 in 38 minutes. What
is the half-life of the reaction?
(ii) (a) Explain the
work obtained in vacuum.
(b) Explain refining of aluminium by Hoope's electrolytic process.
(c) A current of 6 amperes is passed through
AlCl3 solution for 15 min using Pt electrodes, when
0.504 gm Al is produced. What is the molar
mass of Al?
Section: II
Q. 5. Select and
write the most appropriate answer from the given alternatives for each sub
question. [07]
(i) The most
common oxidation state of lanthanoids is
(a) +4 (b) +3 (c) +6
(d) +2
(ii) Which of the following complex will not show
colour?
(a) [Cr(NH3)6]Cl3 (b) K3[VF6]
(c) [Sc(H2O)6]3+ (d) [NiCl4]2-
(iii) Racemate
is
a) Optically
active b) optically dextro rotatory
c) Optically
inactive
d) optically laevorotatory
(iv) The phenol
having lowest acidity is
(v) Schiff's reagent gives pink color with
(a) acetone (b)
acetic acid
(c) acetaldehyde (d)
methylacetate.
(vi) Which of the following
amines is most basic in nature?
a)2, 4 –
Dichloroaniline b)2, 4 -
Dimethylaniline
c)2, 4 –
Dinitroaniline d)2, 4 -
Dibromoaniline
(vii) Night blindness
is due to the deficiency of
(a) vitamin A (b) vitamin B
(c) vitamin C (d) vitamin D
Q. 6. Answer any
SIX of the following. [12]
(i) Why has copper
electronic configuration 3d10 4s1 and not 3d9
4s2?
(ii) Define (a)
ligands (b) Homoleptic complexes
(iii) Write a note on Kharasch- Mayo effect.
(iv) (1) What is the action
of lithium aluminium hydride on but-2-en-1-al.
(2) How will you prepare ethanal
from methanal.
(v) (1) How will you
prepare acetone from calcium acetate.
(2) What is the action of sodium bisulphate on
acetaldehyde.
(vi) (1) How will you prepare nitro ethane from
ethane.
(2) How will you
prepare ethyl amine from nitro ethane.
(vii) (1) What is the action of hot HI on glucose
(2) What is the action of HCN on glucose
(viii) What are soap? How is it
prepared?
Q.7. Answer any
THREE of the following. [09]
(i) Q. Define post lanthanoids. Name two elements that form a pair of
chemical twins. Explain, why are those elements known as chemical twins?
(ii) Write
IUPAC names for the following complexes.
(1) Na3[Fe(C2O4)3]
(2) [Ni(dmg)2]
(3) [PtBr2(NH3)4]Br2
(iii) Write the preparation of isopropyl chloride
using (1) PCl3 (2) PCl5 (3) SOCl2.
(iv) Explain the
mechanism of action of hydroiodic acid on 3-methylbutan-2-ol.
Q. 8. Answer any
ONE of the following. [07]
(i) (a) Define aldol condensation. How will you
prepare but-2-enal from acetaldehyde.
(b) Explain in brief classification of lipids.
(c) Write a note on Nef carbonyl synthesis.
(ii) (a) How is Bakelite
(or formaldehyde phenol) polymer prepared?
(b) Draw the structure of (1) BHA (2) BHT.
(c) (1) Arrange the following acids in their
increasing order of acidic strength.
Acetic acid, Chloroacetic acid,
propionic acid, formic acid.
(2) How will you prepare acetic
acid from dry ice.
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