Can you please give me the Central Board of Secondary Education guess papers of Chemistry 2014?

[Sashwat]

As you want to get the Central Board of Secondary Education guess papers of Chemistry 2014 so here is the information of the same for you:

1. The reaction Cu2+ + 2 Cl-(aq) → Cu(s) + Cl2 (g) has Eºcell = - 1.02 V. This reaction
(A) Can be made to produce electricity in voltaic cell
(B) Can be made to occur in electrolysis cell
(C) Occurs whenever Cu2+ & Cl- are brought together in an aqueous solution
(D) Can occur in acidic but not in basic solution

2. One litre of 1 molar CuSO4 solution is electrolysed. After passing 2F electricity the molarity of CuSO4 will be
(A) M/2 (B) M/4 (C) M (D) 0

3. During the electrolysis of AgNO3 (using Pt electrode) concentration around the cathode as well as anode falls from 4M to 3M. What will happen if this happened with Ag electrode?
(A) Result will remain same
(B) Conc. around cathode will fall from 4 to 3 M but around anode increases from 4 to 5 M
(C) Reverse of statement (B)
(D) Conc. increases from 4 to 5 M on both the electrodes.

4. For the given (Ecell - Eºcell) is – 0.12 V. It will be Zn│Zn2+║Cu2+│Cu then [Zn2+]/ [Cu2+] =?
(A) 102 (B) 10-2 (C) 104 (D) 10-4

5.Pt(H2),(1atm) │pH = 2 ║pH = 3│Pt(H2), (1atm) .The cell reaction for the given cell is:
(A) Spontaneous (B) non – spontaneous (C) equilibrium (D) none

6. Potassium permanganate acts as an oxidising agent in acidic medium. If H+ ion concentration is doubled, electrode potential (in mV) of the half cell MnO4-, Mn2+/Pt will:
(A) Increases by 28.46 (B) Decreases by 28.46 (C) Increases by 14.23 (D) Decreases by 14.23

7.100 ml of a buffer of 1 M NH3 (aq.) and 1 M NH4+ (aq.) are placed in two voltaic cells separately. A current of 1.5 A is passed through both cells for 20 min. If electrolysis of water only takes place
2 H2O + O2 +4 e- → 4 OH- (RHS) 2 H2O → 4 H+ + O2 + 4 e- (LHS)
Then pH of the:
(A) RHS half – cell will increase (B) LHS half – cell will increase
(C) Both half – cells will increase (D) Both half – cells will decrease

8. Standard electrode potential data are useful for understanding the suitability of an oxidant in a Redox titration.
MnO4- (aq) + 8 H+ (aq) + 5 e- → Mn2+(aq) + 4 H2O (l) ; Eº = 1.51 V
Cr2O72-(aq) + 14 H+ (aq) + 6 e- → 2 Cr3+(aq) + 7 H2O(l) ; Eº = 1.38 V
Fe3+ (aq) + e- → Fe2+(aq) ; Eº = 0.77 V & Cl2 (g) + 2e- → 2 Cl- (aq) ; Eº = 1.40 V
Identify the only incorrect statement regarding the estimation of Fe(NO3)2
(A) MnO4- can be used in aqueous HCl (B) Cr2O72- can be used in aqueous HCl
(C) MnO4- can be used in aqueous H2SO4 (D) Cr2O72- can be used in aqueous H2SO4

9. The overall cell reaction for the electrochemical cell
Ag│AgCl(s)│KCl(aq)║AgNO3(aq)│Ag
- +
(A) Ag+ + KCl → AgCl + K+ (B) Ag+ + Cl- → Ag + ½ Cl2
(C) AgCl → Ag+ + Cl- (D) Ag+ + Cl- → AgCl

10. Electrolysis of NaCl solution with inert electrodes for certain period of time gives 600 cm3 of 1 M NaOH in the electrolytic cell. During the same period 31.8 gm of Cu was deposited in a Cu voltameter in series with the electrolytic cell. What is the % current efficiency in the electrolytic cell?
(At wt Cu = 63.6)

(A) 25 % (B) 40 % (C) 50 % (D) 60 %

11. Given the Ksp of compound AgCl, AgBr, AgI is 1.8 × 10-10, 5 × 10-13, 8.3 × 10-17 respectively. Sunal was presented with solution of KI and KCl of unknown concentration. In order to determine conc. of soluble salt he titrated solution with AgNO3 using an electrode to measure change in electrode potential as AgNO3 was added.
At what point does AgCl begin to ppt out of solution

12. Refer to ques 11 above how would graph will change if KBr were present in the mixture, in addition to KI and KCl?
(A) A third endpoint would appear before point A
(B) A third endpoint would appear after point D
(C) A third endpoint would appear, but its location cannot be determined from the provided data
(D) A third endpoint would appear between point B and point D

13. What will be the Ksp of AgCl if the EMF of the following cell is 0.45 V at 25 ºC
Ag│0.1 M AgNO3 ║ saturated NH4NO3│AgCl in 0.1 M KCl│Ag
If it is given that 0.1 M KCl is 85% dissociated and 0.1 M AgNO3 is 82 % dissociated
(A) 1.7 × 10-10 (B) 2 × 10-10 (C) 1.7 × 10-9 (D) 2 × 10-9

14. Which of the following compounds has smaller molar conductance as Molarity tends to zero
(A) HCl (B) NaCl (C) LiCl (D) KCl

15. A property which does not depend on the stoichiometry of the reaction in a cell, at a given temperature is
(A) ΔG (B) ΔH (C) electrical energy produced (D) Eºcell

16. Equivalent conductance of saturated BaSO4 is 400 Ω-1cm2eq-1 and specific conductance is 8 × 10-5 Ω-1cm-1 .Hence Ksp of BaSO4 in M2 is
(A) 4 × 10-8 (B) 1 × 10-8 (C) 2 × 10-4 (D) 1 × 10-4

17. AcOH is titrated with NaOH solution. Which is true statement?
(A) Conductance decreases up to equivalence point, after which it increases
(B) Conductance increases up to equivalence point, after which it decreases
(C) Conductance first increases up to equivalence point and then increases rapidly after equivalence point
(D) None is true

18. Given at 25 ºC;
[Ag(NH3)2]+ + e- → Ag + 2 NH3; Eº = 0.02 V & Ag+ + e- → Ag ;Eº = 0.80 V
Hence order of magnitude of equilibrium constant of the reaction:
[Ag(NH3)2]+ ↔ Ag+ + 2 NH3 will be
(A) 10-10 (B) 10-6 (C) 10-13 (D) 10-18

19. STATEMENT – 1: A saturated solution of KCl is used to make salt bridge in concentration cells.
Because:
STATEMENT – 2: Mobility of K+ and Cl- are nearly same.
(A) Both statements are correct and the statement – 2 is the correct explanation of statement – 1
(B) Both statements are correct and the statement – 2 is not the correct explanation of statement – 1
(C) Statement – 1 is correct but the statement – 2 is incorrect
(D) Statement – 1 is incorrect but the statement – 2 is correct

20. STATEMENT – 1: We cannot add the electrode potential in order to get electrode potential of third electrode if no. of moles of electrons exchanged are not same
Because:
STATEMENT – 2: Electrode potential is an extensive property.
(A) Both statements are correct and the statement – 2 is the correct explanation of statement – 1
(B) Both statements are correct and the statement – 2 is not the correct explanation of statement – 1
(C) Statement – 1 is correct but the statement – 2 is incorrect
(D) Statement – 1 is incorrect but the statement – 2 is correct


Comprehension - Single option correct (+3, -1):

For Ques. No. 21 – 22:
Tollen’s reagent is used for the detection of aldehyde when a solution of AgNO3 is added to glucose with NH4OH when gluconic acid(C6H12O7)is formed.
Ag+ + e- → Ag; Eºred = 0.8 V
C6H12O6 + H2O → C6H12O7 + 2H+ + 2 e-; Eºred = -0.05 V
[Ag(NH3)2]+ + e- → Ag(s) + 2 NH3 ; Eºred = 0.337 V
Data to be used:
At 298 K
2.303 RT = 0.0592 V and F = 38.92
F RT

20. Calculate the value of ln K for the reaction:
Ag+ + C6H12O6 + H2O → C6H12O7 + 2H+ + 2Ag
(A) 66.13 (B) 58.38 (C) 28.30 (D) 46.29

21. When ammonia is added to the solution, pH is raised to 11. Which half cell reaction is affected by pH and by how much?
(A) Eoxid will increase by a factor of 0.65 from Eºoxid
(B) Eoxid will decrease by a factor of 0.65 from Eºoxid
(C) Ered will increase by a factor of 0.65 from Eºred
(D) Ered will decrease by a factor of 0.65 from Eºred
For Ques. No. 23 – 25:
A 4M aqueous solution of NaCl is prepared and 500 ml of this solution is electrolysed. This leads to the evolution of chlorine gas at one of the electrodes.
Given data:
Atomic mass Na = 23, Hg = 200 and 1 Faraday = 96500 coulombs

23. The total number of moles of chlorine gas evolved is
(A) ½ (B) 1 (C) 2 (D) 3

24. If the cathode is a Hg electrode, the maximum weight (gm) of amalgam formed from this solution is
(A) 200 (B) 225 (C) 400 (D) 446

25. The total charge (coulombs) required for complete electrolysis is
(A) 24125 (B) 48250 (C) 96500 (D) 193000



For Ques. No. 26 – 30:
Given passage describes the techniques for the prevention of corrosion
Corrosion of iron can be prevented or at least minimised by shielding the metal surface from oxygen and moisture.
Metal such as Zn, Cr, Sn afford a more durable surface coating for iron. The steel used in making automobiles is coated by dipping into bath of molten Zn, known as galvanising.
Since EºFe2+/Fe = - 0.44 V, EºZn2+/Zn = - 0.76 V
Hence, Zn is oxidised more readily than iron, and it, in turn, reduces Fe2+ to Fe

26. During the prevention of corrosion of iron, by galvanisation, miniature cell set up is:
(A) Fe2+ │Fe║Zn2+│Zn (B) Zn │Zn2+║Fe2+│Fe
(C) Zn │Zn2+, H+║Fe2+│Fe (D) Zn │Zn2+║Fe2+,Fe3+│Fe

27. The technique of protecting a metal from corrosion by connecting it ton a second metal i.e. more easily oxidised is called
(A) Galvanisation (B) Anodic protection (C) Cathodic protection (D) Sacrificial protection

28. Which metal is considered best for protecting the other metal?
EºFe2+/Fe = - 0.44 V, EºZn2+/Zn = - 0.76 V, EºMg2+/Mg = - 2.37 V, EºCu2+/Cu = 0.34 V
(A) Fe (B) Ag (C) Mg (D) Zn

29. In an atmosphere with industrial smog, Cu corrodes to
(A) Cu2(OH)2SO4 (B) Cu2(OH)2CO3 (C) Cu is not corroded (D) Both (A) & (B)

30. Underground steel pipeline is protected by connected it through an insulated wire to a state of Mg. Select incorrect statement about this prevention:
(A) Mg acts as sacrificial anode and corrodes instead of iron
(B) Mg is the cathode and pipeline is the anode with moist soil as electrolyte
(C) Corrosion – prevention is an electrochemical and spontaneous phenomenon
(D) Zn can also be used instead of Mg.
Multiple options correct – One/ more than one option may be correct (+4, 0):

31. The EMF of the cell Zn │Zn2+(aq)║Cu2+(aq)│Cu is dependent on
(A) Temperature (B) Concentration of Zn2+ in solution
(C) Concentration of Zn2+ in solution (D) Quantity of Cu2+ solution Zn2+ solution

32. Which of following is/are incorrect?
(A) The conductance of 1 unit3 of a solution is called specific conductance
(B) Specific conductance increases while molar conductivity decreases on progressive dilution
(C) The limiting equivalent conductivity of weak electrolyte cannot be determined directly by extrapolation of the plot of Ʌeq against c
(D) The conductance of metals is due to the movement of free electrons

33. Which of the following expression represents the voltage of cell at 298 K
Ag(s) │AgI (saturated solution 1) ║Ag2C2O4 (saturated solution 2) │Ag(s)
Then Ecell =?
(A) 0.059 log [Ag+]1 (B) 0.059 log Ksp(Ag2C2O4)
[Ag+]2 Ksp (AgI)
(C) 0.059 log [Ag+]2 (B) 0.059 log [2Ksp(Ag2C2O4)]1/3
[Ag+]1 [Ksp (AgI)]1/2

34. Whenever the electrical energy i.e. nFE is equal, or greater or less than the heat of reaction (- Δ H) depends upon the sign of (E/T)P i.e., upon the sign of temperature coefficient of the emf of the cell. If (E/T)P > 0, then
(A) The emf of the cell will increase with increase of temperature
(B) The electrical energy will be greater than the heat of reaction
(C) Additional energy will be supplied to the cell by surroundings
(D) If no additional energy is supplied by the surroundings, temperature of the cell will fall during its working.

35. Choose the concentration cell(s)?
(A) Pb(Hg),m1│Pb2+(aq)│Pb (Hg),m2
(B) Pt, H2(1 atm)│HCl│Cl2(1 atm), Pt
(C) Pt, H2(2 atm)│HCl│H2(1 atm), Pt
(D) Ag(s), AgCl(s)│KCl,m1║KCl,m2│AgCl(s),Ag(s)
[where m stands for molality]


Integer Type (+3, 0)

36. Out of following total number of extensive property
Molar conductivity, heat capacity, resistance,electromotive force, resistivity.

37. Among the following, the number of elements showing only one non – zero oxidation state is
O, Cl, F, N, P, Sn, Tl, Na, Ti

38. Three plots for conductance(y - axis)(in mS) Vs volume(x - axis) (in ml) are shown below
Pick correct curve for : AcOH (aq.) was added to an aqueous NH4OH gradually and conductivity of the solution was measured.

39. Consider the following cell reaction:
2 Fe(s) + O2 (g) + 4 H+ (aq) → 2 Fe2+ (aq) + 2 H2O (l) Eº = 1.67 V
At [Fe2+] = 10-3 M, P(O2) = 0.1 atm and pH = 3, calculate the cell potential at 25 ºC (Divide the answer you obtained by 0.19)
40. A 200 W, 110V incandescent lamp is connected in series with an electrolytic cell of negligible resistance containing a solution of zinc chloride. What weight of zinc will be deposited from the solution on passing the current for 30 minutes? (Zn = 65.4)

Matrix match (+5 for full correct, +1 for single row correct):
41.
(Electrolyte Subjected to electrolysis) (Species obtained at the electrode)
(A) Dil HCl solution (p) At anode O2(g) is evolved
(B) Dil NaCl solution (q) At cathode H2(g) is evolved
(C) Conc NaCl solution (r) At anode Cl2(g) is evolved
(D) Fairly conc AgNO3 solution (q) At cathode Ag(s) is deposited

1. What is Glycosidic linkage ? [1]
2. Write the structure of 2-Methylcyclohexanone. [1]
3. Why is Zinc not considered to be a Transition element though it is present in the First [1]
series of Transition elements ?
4. Give the IUPAC name of [Co(NH3)4(H2O)2]Cl3 [1] 5. Why do Transition metals form Complex compounds ? [1]
6. What are Reducing sugars ? [1]
7. What is Homogeneous catalysis ? [1]
8. Why does the conductivity of a solution decrease with dilution ? [1]
9. Silver crystallizes in fcc lattice. If the edge length of the cell is 4.077 x10-8 cm and density [2]
is 10.5 g cm-3,calculate the atomic mass of silver.
10. i) Ionic solids conduct electricity in molten state but not in solid state.Why ? [2]
ii) Give one difference between Frenkel defect and Schottky defect.
11. Zinc/Silver cell is used in hearing aids and electric watches : [2]
Zn ----- Zn2+ + 2 e- , E0 = -0.76 V
Ag2O + H2O + 2e- -- 2Ag + 2 OH- , E0 = 0.344 V
i)Which are the oxidized and reduced species in the above cell ?
ii) Find E0 of the cell and ΔrG0 in joules.
12. Define conductivity and Molar conductivity for the solution of an electrolyte. Discuss their [2]
Variation with concentration.

13. Explain why [Co(NH3)6]3+ is an inner orbital complex while [Ni(NH3)6]2+ is an outer orbital [2]
complex..
OR
What is Crystal field splitting energy ? How does the magnitude of Δo decide the actual
configuration of d orbitals in a coordination entity ?
.

14. i) State Raoult’s law for a binary solution containing volatile components. [2]
ii) What is the effect of the addition of non volatile solute on the vapour pressure of pure liquid ?
15. i) Why do primary Amines have higher boiling point than tertiary amines ? [2]
ii) Why are aliphatic amines stronger bases than aromatic amines ?

16. State reasons : [2]
i) Ethylamine is soluble in water whereas Aniline is not.
ii) Aromatic primary amines cannot be prepared by Gabriel phthalimide synthesis.
OR
What happens when :
i) Aniline reacts with bromine water at room temperature .
ii) Aniline is treated with Sodium nitrite and dilute Hydrochloric acid at 273 K.
17. Bring about the following conversions : [2]
i) Phenol to Salicyaldehyde.
ii) Ethanal to Pentan-2-ol.
18. Explain the following : [2]
i) Boiling point of Ethanol is higher than that of Methoxymethane.
ii) Mixture of o-nitrophenol and p- nitrophenol can be separated easily.

*19. Anees went for mountaineering.He had to carry an oxygen cylinder and cope with breathing [3]
problem.Decreased pressure decreases the solubility of gases in blood.
• What do the mountaineers experience when they reach the top ? Why ?
• Name and State the law which is related to the above observation.

20. a) Draw the structures of following molecules : i) H2S2O7 ii) XeF4 [3]
b) Why do Noble gases have very low boiling points ?

21. State reasons for the following : [3]
i) The third Ionisation enthalpy of Mn is exceptionally high.
ii) Cu+ is colourless but Cu2+ is coloured.
iii) Among transition metals,the highest oxidation state is exhibited in Oxoanions of a metal.

22. Describe the principle involved in each of the following processes of metallurgy : [3]
i) Froth floatation method
ii) Zone refining of metals
iii) Mond’s process

23. Complete the following reactions : [3]
i) CH3CH=C(CH3)2 + HBr -------
ii) CH3CH2CH2OH + SOCl2 -----------
iii) CH3CH2Br + Mg ---------

24. i)What are Essential and Non-essential Amino acids ? [3]
ii) Name the four bases of DNA and RNA.

25. i) What are Antibiotics ? Give examples. [3]
ii)What are Artificial sweetening agents ?
iii)Give one difference between Antiseptic and Disinfectant.

26. i) Differentiate between Copolymer and Homopolymer with example. [2+1]
ii) What is the significance of 6,6 in Nylon-6,6 ?

27. Account for the following : [3]
i) Most of the medicines are colloidal in nature.
ii) Sky appears blue in colour .
iii) Gas mask is used for breathing in coal mines.

28. a) The thermal decomposition of HCOOH is a first order reaction with a rate constant of 2.4 x10-3 s-1 [3+2]
at a certain temperature.Calculate how long will it take for three-fourths of initial quantity of
HCOOH to decompose.
b) Explain the following terms :
i) Rate of a reaction.
ii) Activation energy of a reaction.
OR
a)The half life for radioactive decay of 14C is 5730 years.An archeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample.
b) Explain the following terms :
i) Order of a reaction.
ii) Molecularity of a reaction.


29. a) Give simple chemical tests to distinguish between the following pairs of compounds - [2+3]
i) Propanal and Propanone ii) Acetophenone and Benzaldehyde
b) An Organic compound ‘A’ (Molecular formula C8H8O) neither reduces Tollens or Fehlings reagent nor
does it decolourise Bromine water.On drastic oxidation with Chromic acid , it gives a carboxylic acid ‘B’
having formula C7H6O2. ’C’. Organic compound ‘A’ gives yellow precipitate ‘C’ on heating with Iodine
in the presence of Sodium hydroxide.Identify A ,B & C and write all the reactions involved .
OR

a) Illustrate the following name reactions –
i) Canizzaro reaction ii) HVZ reaction
b) How will convert the following :
i) Benzoic acid to Benzamide
ii) Phenol to Benzoic acid
iii) Methy chloride to Methoxymethane
30. a) Complete the following reactions :- [2+3]
i) C + H2SO4 (conc.)--------------
ii)Cu + HNO3 (conc.)------------
b) Account for the following :
i) H3PO2 is a stronger reducing agent than H3PO3.
ii) HF has highest boiling point while HCl has lowest boiling point among hydrogen halides.
iii) Interhalogen compounds are more reactive than halogens from which they are formed.
OR
a)What happens when :
i) Chlorine is passed through a hot concentrated solution of NaOH.
ii) Ammonium nitrate is heated.
b) Explain the following observations :
i) PCl3 fumes in moist air.
ii) N2 is a gas while P4 is a solid.
iii) All Halogens are coloured.

1. What is Peptide linkage ? [1]
2. Write the structure of Benzene-1,2-dicarbaldehyde. [1]
3. Which transition metal in the first transition series shows highest paramagnetism ? [1]
4. Give the IUPAC name of [Co (NH3)5Br] SO4. [1] 5. Which is a stronger reducing agent : Cr2+ or Fe2+ ? Why ? [1]
6. What are Reducing sugars ? [1]
7. What is Shape selective catalysis ? [1]
8. Why does the conductivity of a solution decrease with dilution ? [1]
9. A body centred cubic element of density 10.5 g cm-3 has a cell edge of 409 pm.Calculate [2]
its atomic mass.

10. i) Ionic solids conduct electricity in molten state but not in solid state.Why ? [2]
ii) Which substances show Frenkel defect ?
11. Zinc/Silver cell is used in hearing aids and electric watches : [2]
Zn ----- Zn2+ + 2 e- , E0 = -0.76 V
Ag2O + H2O + 2e- -- 2Ag + 2 OH- , E0 = 0.344 V
i)Which are the oxidized and reduced species in the above cell ?
ii) Find E0 of the cell and ΔrG0 in joules.
12. Define conductivity and Molar conductivity for the solution of an electrolyte. Discuss their [2]
Variation with concentration.

13. Explain why [Cr(NH3)6]3+ is paramagnetic while [Ni(CN)4]2- is diamagnetic. [2]
OR
Draw the structures of geometrical isomers of [Fe(NH3)2(CN)4]- and [Pt(NH3)(H2O)Cl2]
.

14. i) State Raoult’s law for a binary solution containing volatile components. [2]
ii) What is the effect of the addition of non volatile solute on the vapour pressure of pure liquid ?
15. Arrange the following : [2]
i) In increasing order of basic strength : C6H5NH2,C6H5N(CH3)2,(C2H5)2NH & CH3NH2.
ii) In increasing order of boiling point : C2H5OH,(CH3)2NH,C2H5NH2.

16. State reasons : [2]
i) pKb value of Aniline is more than that of Methylamine.
ii) Aromatic primary amines cannot be prepared by Gabriel phthalimide synthesis.
OR
What happens when :
i) Aniline is treated with concentrated Sulphuric acid.
ii) Aniline is treated with Sodium nitrite and dilute Hydrochloric acid at 273 K.
17. Bring about the following conversions : [2]
i) Phenol to Acetophenone.
ii) Ethanal to Butan-2-ol.
18. Explain the following : [2]
i) Boiling point of Ethanol is higher than that of Methoxymethane.
ii) Mixture of o-nitrophenol and p- nitrophenol can be separated easily.

*19. An antifreeze is a chemical additive which lowers the freezing point of a water-based liquid. [1+2]
An antifreeze mixture is used to achieve freezing-point depression for cold environments and
also achieves boiling-point elevation("anti-boil") to allow higher coolant temperature. Freezing
and boiling points are colligative properties of a solution, which depend on the concentration of
the dissolved substance. Because water has good properties as a coolant , antifreeze is used
in internal combustion engines and solar water heaters. The purpose of antifreeze is to
prevent a rigid enclosure from undergoing catastrophic deformation due to expansion when
water turns to ice.
i) What are Colligative properties ?
ii) Determine the molarity of an antifreeze solution containing 250 g water mixed with 222 g
Ethylene glycol( C2H6O2).The density of this solution is 1.07 g/ml.

20. a) Draw the structures of following molecules : i) H4P2O5 ii) XeOF4 [3]
b) Why do Noble gases have very low boiling points ?

21. State reasons for the following : [3]
i) The third Ionisation enthalpy of Mn is exceptionally high.
ii) Cu+ is colourless but Cu2+ is coloured.
iii) Among transition metals,the highest oxidation state is exhibited in Oxoanions of a metal.

22. Describe the principle involved in each of the following processes of metallurgy : [3]
i) Froth floatation method
ii) Zone refining of metals
iii) Elecrolytic refining

23. Complete the following reactions : [3]
i) CH3CH=C(CH3)2 + HBr -------
ii) (CH3)3CBr + KOH ------ETHANOL,Heat-----
iii) C6H5Cl + Mg ---------

24. i)What are Essential and Non-essential Amino acids ? Give one example of each. [3]
ii) What are Nucleic acids ?

25. i) What are Antibiotics ? Give examples. [3]
ii)Why is the use of aspartame limited to cold drinks and cold foods ?
iii)Give one difference between Antiseptic and Disinfectant.

26. i) Differentiate between Thermoplastic and Thermosetting polymers with example. [2+1]
ii) Name one Biodegradable polymer and its monomers.

27. i) How are the two Emulsions different from one another ? Give example for each. [3]
ii) Explain what is observed when an electrolyte NaCl is added to Hydrated ferric oxide solution .

28. a) The thermal decomposition of HCOOH is a first order reaction with a rate constant of 2.4 x10-3 s-1 [3+2]
at a certain temperature.Calculate how long will it take for three-fourths of initial quantity of
HCOOH to decompose.
b) Explain the following terms :
i) Rate of a reaction.
ii) Activation energy of a reaction.
OR
a)The half life for radioactive decay of 14C is 5730 years.An archeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample.
b) Explain the following terms :
i) Order of a reaction.
ii) Molecularity of a reaction.


29. a) Give simple chemical tests to distinguish between the following pairs of compounds - [2+3]
i) Phenol and Benzoic acid ii) Acetophenone and Benzaldehyde
b) An Organic compound ‘A’ (Molecular formula C8H16O2) was hydrolysed with dilute sulphuric acid
to give a carboxylic acid ‘B’ and an Alcohol ’C’. Oxidation of ‘C’ with chromic acid produced ‘B’.
‘C’ on dehydration gives But-1-ene.Identify A ,B and C and write all the reactions involved .
OR

a) Illustrate the following name reactions –
i) Aldol condensation reaction ii) HVZ reaction
b) How will convert the following :
i) Benzoic acid to Benzamide
ii) Propanoic acid to Propanol
iii) Propanal to Butanone
30. a) Complete the following reactions :- [2+3]
i) XeF2 + H2O --------------
ii) PH3 + CuSO4 ------------
b) Account for the following :
i) Pentavalent Bismuth is a strong oxidizing agent.
ii) Hydrogen fluoride is much less volatile than Hydrogen chloride.
iii) Nitrogen shows Catenation property less than Phosphorus.
OR
a)What happens when :
i) Chlorine is passed through a hot concentrated solution of NaOH.
ii) Ammonium dichromate is heated.
b) Explain the following observations :
i) Red phosphorus is less reactive than white phosphorus.
ii) Dinitrogen is inert at room temperature.
iii) Interhalogens are more reactive than Halogens.

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