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11. |
KMnO4 is acidified using H2SO4 in titrations and HCl is not used because (a) H2SO4 is stronger acid than HCl (b) HCl is oxidised to Cl2 by KMnO4 (c) H2SO4 is dibasic acid (d) rate of reaction
is faster in presence of H2SO4 |
1 |
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12. |
The slope of the following graph is
(a) (b) (c) k (d)
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1 |
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For question number 13 to 16 two
statements labelled as Assertion (A) and Reason
(R Select the most appropriate answer from the options given
below: (a) Both A and R are true
and R is the correct explanation of A (b) Both A and R
are true but R is not the correct
explanation of A. (c) A is true but R is false. (d) A is false but R is true. |
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13. |
Assertion: Conductivity of a solution decreases with decrease in concentration.
Reason: The number of ions per unit volume of solution decreases. |
1 |
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14. |
Assertion: D (+)
Glucose is dextrorotatory in nature. Reason: ‘D’ represents its dextrorotatory nature. |
1 |
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15. |
Assertion:
Aryl halides undergo nucleophilic substitution reactions more easily. Reason: The carbon halogen
bond in aryl halides has partial double
bond character. |
1 |
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16. |
Assertion: Sodium hydrogen sulphite adds to aldehydes and ketones to form the addition product. Reason: Reaction of aldehydes with Sodium hydrogen sulphite is useful
for separation and purification of aldehydes. |
1 |
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SECTION B This section contains 5 questions with
internal choice in one question. The following
questions are very short answer
type and carry
2 marks each. |
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17. |
(a). Define molality. (b).
Give an example
for Solid-Solid solution |
1 1 |
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18. |
What happens when (i) Phenol reacts with bromine water? (ii) Anisole reacts with HI? Write the chemical equations involved in the above reactions. |
1 1 |
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19. |
Name the nitrogenous bases present in RNA. Which
one of these
is not present
in DNA? |
1+1 |
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20. |
Arrange the following compounds in increasing order of property mentioned within brackets. (a) CH3CHO, CH3CH2OH, CH3OCH3, CH3CH2CH3 (boiling point) (b) Ethanal, Propanal, Propanone, Butanone (reactivity towards
nucleophilic addition reaction) |
1+1 |
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21. |
A first order
reaction has rate constant of 1·15 x 10-3 s-1.
How long will
5 g of this reactant take
to reduce to 3g? (log
5 = 0.6990 , log 3=0.4771) |
2 |
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SECTION C This section contains 7 questions with
internal choice in one question. The following questions are short answer
type and carry
3 marks each |
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22. |
Write Nernst
equation for the cell in which the following reaction takes place Mg(s) + 2Ag+(0.0001M) → Mg2+(0.130M) +
2Ag(s) Calculate its 𝐸𝐶𝑒𝑙𝑙 if
𝐸𝑂 2+ = -2.36
V and 𝐸𝑂 1+ = 0.81 V (log 13=1.114) 𝑀𝑔 /𝑀𝑔 𝐴𝑔 /𝐴𝑔 |
3 |
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23. |
(a) Identify the chiral
molecule in the following pair: (i) 3-methylbutan-2-ol (ii)
2,4-dimethylbutan-3-ol (b) Write the structure of the product when Chlorobenzene is
treated with methyl chloride in the presence of sodium metal
and dry ether. (c) Write the structure of the alkene formed by
dehydrohalogenation of 1-bromo-1- methylcyclohexane with alcoholic KOH |
1 1 1 |
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24. |
(a) Draw the Geometrical isomers
of [ Pt(en)2Cl2]2+ and name the optically active isomer. (b)
On the basis of crystal field
theory write the electronic configuration for d5 ion for which Δo < P |
2 1 |
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25. |
(a)
Draw the Zwitter
ion structure of Alanine CH3CH(COOH)(NH2) (b)
Lysine is an essential amino acid. Give reason. (c)
Give
differences between Fibrous and Globular protein (or) (c) Define denaturation of protein. Name
the structure of protein that
remains intact after denaturation |
1 1 1 |
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26. |
(a) pKa of chloroacetic acid is smaller
than acetic acid.
Give reason. (b) Write chemical reaction for : i) HVZ reaction ii) Gattermann-Koch reaction |
1 2 |
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27. |
(a) Explain the mechanism of dehydration of ethanol to ethene. (b) write the
chemical equation for
the conversion of Ethyl magnesium chloride to propanol |
2 1 |
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28. |
(a) The rate constants of a reaction at 200K and 500K are 0.02s–1 and 0.20s–1 respectively. Calculate the value of Ea (Given
2.303R = 19.15
JK-1mol-1) (b) Define Collision frequency. |
2 1 |
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SECTION D The following questions are case-based questions. Each question has an internal choice and
carries 4 (1+1+2) marks each. Read the passage carefully and answer the questions that follow. |
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29. |
Coordination compounds contain a
metallic element as the central atom and are therefore referred to as metal complexes. These types of coordination complexes generally consist of a
transition element as the central atom. It can be noted that the central atom in these complexes is called the
coordination centre. A chemical compound in which the central ion
or atom (or
the coordination centre) is bound to a set
number of atoms, molecules, or ions is called a coordination entity. Some examples of such coordination entities include [CoCl3(NH3)3] and [Fe(CN)6]4-. In coordination compounds, the central atoms
or ions are typically Lewis
Acids and can, therefore, act as electron-pair acceptors. The atoms,
molecules, or ions that are bound to the coordination centre or the
central atom/ion are
referred to as ligands. These ligands can either be a simple
ion or molecule, such as Cl– or
NH3 or in the form of relatively large
molecules, such as ethane-1,2-diamine (NH2- |
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CH2-CH2-NH2). The coordination
sphere is the non-ionizable part of a complex compound, which consists of a central transition metal
ion surrounded by neighbouring atoms or groups enclosed in a square
bracket. (a)
Write down the formula
of: Tetraamineaquachloridocobalt(III) chloride. (b) Calculate the coordination number
of Co in [Co(en)3]3+. (c) Give
Chemical test to distinguish between [Co(NH3)5Br]SO4 and [Co(NH3)5SO4]Br. (or) Describe
the shape and magnetic behaviour of the complex [Co(NH3)6]3+. (At.no. of Cu=29) |
1 1 2 2 |
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30. |
Electricity can be produced when electrons move from one
element to another in certain types of reactions (such as redox reactions).
Typically, electrochemistry deals with the overall reactions when multiple
redox reactions occur simultaneously, connected via some external electric
current and a suitable electrolyte. In other words, electrochemistry is also
concerned with chemical phenomena that involve charge separation (as seen
commonly in liquids such as solutions). The dissociation of charge often involves
charge transfer that occurs homogeneously or heterogeneously between
different chemical species. A spontaneous chemical process
is one which
can take place
on its own, and in such a process, the Gibbs free energy
of a system decreases. In electrochemistry, spontaneous reaction (redox
reaction) results in the conversion of chemical energy into electrical
energy. The reverse process is also possible where a non- spontaneous chemical reaction occurs by
supplying electricity. These interconversions are carried out in equipment called an electrochemical cell. (a)
Name the electrochemical cell
generally used in hearing aids. (b) ∧m of CH3COOH increases drastically while that of CH3COONa increases
gradually on dilution. Explain (or) Can copper sulphate solution be stored
in zinc pot? Explain. (𝐸0 2+ = −0.76𝑉 , 𝐸0 2+ = 0.34𝑉) 𝑧𝑛 /𝑧𝑛 𝐶𝑢 /𝐶𝑢 (c)
The standard electrode potential for Daniell cell
is 1.1 V. Calculate the standard Gibbs energy
for the cell reaction. (F = 96,500
C mol-1) |
1 1 1 2 |
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SECTION E The following
questions are long answer type and carry 5 marks each. All questions
have an internal choice. |
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31. |
Attempt any five of the following: (a)
Which of the following ions will have
a magnetic moment
value of 1.73
BM. Sc3+,
Ti3+,
Ti2+,
Cu2+,
Zn2+ (b)
In
order to protect iron from corrosion, which one will you prefer as a sacrificial electrode, Ni or Zn? Why? (Given
standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -0.76
V respectively.) (c)
The second
ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain
the lower value
of Mn. (d) Give two similarities in the properties of Sc and Zn. (e) What is actinoid contraction? What causes
actinoid contraction? (f) The transition metals and their compounds act as good catalysts. Give reason (g)
Write the ionic equation for reaction of KI with acidified KMnO4. |
1x5 |
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32. |
(a)
How will you convert
the following : (i) Benzoic acid to aniline (ii) Aniline to p-bromoaniline (b)
Why aniline does not give
Friedel-Crafts reaction? (c)
Arrange the following in the increasing order of their
pKb values : C6H5NH2, NH3, C2H5NH2, (CH3)3N (d) Give a test to distinguish between
CH3CH2NH2 and (CH3CH2)2NH. (or) (a) An aromatic compound
‘A’ on treatment with aqueous ammonia and heating forms compound ‘B’ which on heating with Br2 and KOH forms a compound ‘C’ of molecular formula C6H7N. Write the structures and IUPAC names of compounds A, B and C. (b) Explain with
equation
Gabriel
Phthalimide reaction
for
the
preparation of primary amines. |
2 1 1 1 3 2 |
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33. |
(a)
State Henry’s
law. (b)
Give two differences between
ideal and non-ideal solution. (c) Calculate
the boiling point of solution when
4g of MgSO4 (Molar mass:120g/mol) is dissolved in 100g of water, assuming MgSO4 undergoes
complete ionization. [Kb for water =0.52 K kg mol-1] (or) (a) Define azeotropic mixture. (b) What happens when
red blood cells
are placed in 0.1 %( m/v) NaCl
solution? (c) The Vapour
pressure of water
at 20ºC is 17.5 mm Hg. Calculate the vapour pressure of water at 20ºC when
25 g of glucose (Molar
mass = 180
g mol-1) is dissolved in 150 g of water. |
1 1 3 1 1 3 |
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