`CHEMISTRY
Paper – 1
(THEORY)
Three hours and a quarter
(The first 15 minutes of the examination are for reading the paper only.
Candidates must NOT start writing during this time).
------------------------------------------------------------------Answer all questions in Part I. From Part II, answer any four questions from Section A, any
three questions from Section B and any two questions from Section C.
All working, including rough work, should be done on the same sheet as, and adjacent to the rest
of the answer in the answer booklet.
The intended marks for questions are given in brackets [ ].
Balanced equations must be given wherever possible and diagrams where they are helpful.
When solving numerical problems, all essential working must be shown.
In working out problems, use the following data:
Gas Constant R = 1.987 cal deg-1 mol-1 = 8.314 JK-1 mol-1 = 0.0821 dm3 atm K-1 mol-1
-----------------------------------------------------------------------------------------------------------PART I (40 marks)
Answer all questions.
Question 1.
(a)
Correct the following statements by changing the underlined words.
(i)
Ethanoic acid dimerises in solution. Its molecular mass determined from its
depression of freezing point of the solution will be same as theoretical value
(ii)
When gas undergoes expansion the entropy remains same.
(iii)
One Faraday of electricity can deposit 54 grams of silver.
(iv)
Alkaline hydrolysis Ethyl Acetate forms sodium acetate and ethyl alcohol. It is third
order reaction
(v)
Benzyl and allyl carbonium ions are stable due to + I effect
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[5]
(b)
Each question below is followed by four possible choices of answers.
Choose the correct answer and write it in your answer booklet.
(i)
The solution having the highest freezing point is
A
0.2 M glucose.
B
0.1 M BaCl2.
C
0.2 M NaCl.
D
0.1 M urea.
(ii)
Copper is better oxidizing agent than Zinc because:
[10]
A
both copper and zinc have a positive reduction potential.
B
reduction potential of zinc is higher than that of copper
C
reduction potential of copper is higher than that of zinc
D
both zinc and copper have negative reduction potential
(iii)
Which of the following is true for a spontaneous process at low conditions of temperature?
A
ΔS = +ve; ΔH = +ve
B
ΔS = +ve; ΔH = -ve
C
ΔS = -ve; ΔH = -ve
D
ΔS = -ve; ΔH = +ve
(iv)
Buffer solution is mixture of:
(v)
A
weak acid and strong base
B
weak base and strong acid
C
weak acid and its salt with strong base
D
weak acid and its conjugate acid
The monomers of Dacron are :
A
ethane 1,2- diol and 1,4-benzene dicarboxylic acid
B
formaldehyde and phenol
C
ethane 1,2- diol and 1,2-benzene dicarboxylic acid
D
styrene
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(vi)
Which of the following has highest bond dissociation energy :
A
H2
B
O2
C
N2
D
O22-
(vii)
The compound which shows little rise in solubility with increase in temperature and
continuous solubility curve is :
A
CaSO4
B
CaCrO4
C
NaCl
D
Na2SO4
(viii)
Which of the following is most commonly possessed by nucleophile?
A
B
C
D
(ix)
positive charge
vacant orbital
accept electron
lone pair
Nitriles on reduction gives:
A. 10 amine
B. 20 amine
C. 30 amine
D. Quarternary salt
(x)
The process in which benzaldehyde is prepared from toluene oxidation by
chromyl chloride is:
A.
B.
C.
D.
William synthesis
Rosenmund’s reaction
Wurtz-fittig reaction
Etard reaction
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(c)
Fill in the blanks choosing appropriate word/s given in the brackets. Write the correct
answers in your answer booklet.
[5]
(TEL, ferrocene, TΔS, zero, Silver nitrate, Hypo, 15,16, 32, 33,collisions,Frenkel, Schotky )
(i)
15P
32
undergoes β emission. The product formed has atomic number……….and mass
number...………..
(ii)
(d)
……….defect volume and density remains unchanged.
(iii)
For a system to be in equilibrium, ΔH should be equal to ……...
(iv)
The chemical name for lunar caustic is………. .
(v)
……………..is example of pie bonded organometallic compound.
Match the items of column A with the items in column B. Rewrite the correct pairs
in your answer booklet.
[5]
Column A
Column B
(i) acetic acid
a) salicylic acid
(ii) α-hydrogen
(b) functional isomerism
(iii) phenol
(c) Grignard reagent
(iv) 2-butanol
(d) aldol
(v) ethers
(e) geometrical isomerism
(f) optically active
(g) Acetaldehyde
(h) carbonate test
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(e)
Answer the following questions.
(i) Distinguish between thermoplastics and thermosetting plastics
[2]
(ii)
What is thermal death
[1]
iii)
What is the projectile that should be used to bombard 13 Al27 to obtain 14Si30
and a proton?
[1]
(iv)
What is isoelectric point of glycine? What happens to glycine in basic medium? 2
(v)
Give reasons for the following:
a) The voltage or current drops to zero if salt bridge is pulled out.
[2]
b) Aldehyde and acetone give similar type of reaction
(vi)
A 0.02M NaCl solution offered a resistance of 62 ohms in a conductivity cell. If the
cell constant of the cell is 0.367 cm-1, what would be the molar conductivity? [2]
(vii) Name the properties of colloidal solutions involved in the following applications: [1]
I.
II.
(viii)
purification of water
cleansing action of soap
In the following reaction name the type of reagent and type of reaction
i) C6H6 + Cl+
ii) CH3COCH3 + HCN
C6H5Cl + H+
CH3CO(OH)(CN)CH3
[1/2 x 4=2]
(ix)
Give the balanced chemical equations for the preparation of polymer nylon 66.
(X)
How can you separate type I solution?
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[1]
PART II
SECTION A (28 marks)
Answer any four questions.
Question 2.
(a)
A solution of a non-volatile solute with molecular mass 342 is obtained by dissolving
17.1 gm of it in 500 gm of water. Calculate the osmotic pressure of the solution at 27°C. [2]
(b)
Compare crystals of copper and diamond and indicate one similarity and one difference. [2]
(c)
Complete and balance the following nuclear equations.
25
12Mg
(i)
(γ, p)
C ( stable)  .....  137 N  0 n1
12
6
(ii)
(d)
[2]
Differentiate between pyro electricity and piezoelectricity?
[1]
Question 3.
(a)
Predict the hybridization, shape, bond angle of Ammonia molecule according to VSEPRT.
Support your answer with suitable reasons.
(b)
[2+1]
The solubility of CaF2 is 2.5 x 10-4 mol l-1, find the solubility product? Will its solubility
increase or decrease in the solution of CaCl2?
(c)
What is unit cell
[2 + 1]
[1]
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Question 4.
(a)
The rate of first order reaction is 3  10-3 mol L-1 s-1 when the concentration of reactant A
is 0.1M. What will be the rate of reaction when the concentration of the reactant is
0.01M?
[2]
(b)
Give the molecular orbital configuration of superoxide and peroxide and predict the magnetic
properties.
(c)
[2]
Give reasons for the following:
[3]
a) graphite is soft and slippery
b) Solid NaCl starts separating on passing HCl gas through NaCl solution.
c) N2+ and N2- have same bond order but N2+ is slightly more stable.
Question 5.
(a)
Calculate the emf of the following cell at 25°C:
Mg / Mg2+ (0.10M)║Ag+ (1x 10 - 4 M) / Ag,
E0 for Mg and Ag electrodes are -2.37 volts and 0.8 volts respectively.
(b)
Draw a phase diagram of one component system. Explain triple point and metastable
equilibrium.
(c)
[2]
[2]
The bones of a prehistoric animal were found to have C14 activity of 1.53 disintegration
per second. How long ago did the animal live? The current C14 activity is 15.3
disintegration per second.
[2]
14
( T1 of C=5730 yrs.)
2
(d) Explain auto catalyst with one example
[1]
Question 6.
a) An aqueous solution of organic compound contains 12g of solute per litre. When it is treated
with 100 ml of ether 8 g of solute is extracted. How much solute will be extracted from the
aqueous solution by adding further 100 ml of ether.
[2]
b) What is specific conductance of a solution and what is its unit? How is it
related to the equivalent conductance of the solution?
[2]
c) What is the activation energy of a reaction? How is the rate constant of a reaction
related to the activation energy? How can activation energy be calculated from
this relationship?
[3]
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SECTION B (18 marks)
Answer any three questions.
Question 8.
(a)
Name one chief ore of copper and explain how copper is extracted from its ore.
[3]
(b)
Explain mesomeric effect with an example
[1]
(c)
Write the balanced equation to show oxidizing and reducing property of H2O2
[2]
Question 9.
a) Explain how iodine is manufactured from sea weeds and give a balanced chemical
equation.
b) Complete the following reactions:
[3]
a) 2Na2S2O3 + I2
b) 6NaOH + 3Br2→
c) H2S + FeCl3
c) What is Wilkinson Catalyst
[1]
Question 10.
(a)
Name the compound given below
I.
II.
(b)
[2]
[Cu(H2O)2(NH3)4]SO4
K3[Co (CN)5NO]
Give reasons for the following
[2]
a. Alkene react as nucleophile
b. In SN1 reaction rate remains same even if con. Of alkali is doubled.
(c ) One mole of a gas is allowed to expand isothermally and reversibly from volume
of 1 cm3 to 50cm3 at 273K. Calculate W and q .
[2]
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Question 11.
(a)
Give the difference between following pairs
[2]
1. Free radical and electrophile
2. Electrophilic substitution and nucleophilic substitution reaction.
(b)
What is first law of thermodynamics? Give its mathematical form and limitations.
(c)
Enthalpy change and entropy change of a chemical reaction at 250C are 177 KJ and 160.4 JK-1
(d)
[2]
respectively. Calculate free energy of the reaction and predict the reaction
[1]
Explain –I effect with example.
[1]
SECTION C (14 marks)
(Answer any two questions.)
Question 12.
(a)
An organic compound (A) on treatment with acetic acid in the presence of Sulphuric
acid produces an ester (B). (A) on mild oxidation gives (C). (C) reduces Tollen’s
reagent to give silver mirror and (D). (D) on reacting with Phosphorous pentachloride
followed by ammonia gives (E). (E) on dehydration produces methyl cyanide.
(b)
(c)
Identify (A), (B), (C), (D) and (E) and write the relevant reactions.
[2]
Write the balanced chemical equation for the following conversions:
[2]
(ii)
Amide to amine
(iii)
Aniline to benzoic acid
Give one distinguishing test between the following pairs:
I.
II.
III.
[3]
Benzaldehyde and formaldehyde
Acetone and acetaldehyde
Starch and cellulose
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Question 13.
(a)
(b)
(c)
Write the isomers of:
(i)
C4H4O4
(ii)
Tartaric acid
[2]
Give balanced equation for the following reaction
(i)
Formaldehyde to urotropin
(ii)
Fat to soap
(i)
Glucose to osazone
(ii)
Carbylamine reaction
[4]
What is the monomer of Teflon? Give the structure
[1]
Question 14.
(a)
Give the balanced chemical equation for the following.
(i)
Wohler synthesis
(ii)
Haloform reaction of acetone
(iii)
Reduction of nitrobenzene in acidic medium
[3]
D
KCN
A
(b)
( c)
C6H6
B
C6H5CH3
C
C6H5CHO
C6H5CH2OH + C6H5COOH
Identify A, B, C D
[2]
Differentiate between the following pairs with examples:
[2]
(i)
Addition and condensation polymer
(ii)
homo and co polymer
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