KENDRIYA VIDHYALAYA SANGATHAN- AHMEDABAD REGION

SESSION ENDING EXAMINATION: MARCH-14

CLASS-XI

SUBJECT:-CHEMISTRY

TIME:3 HOURS M M:70

General Instruction:

1. All questions are compulsory.
2. Questions number 1 to 5 are very short answer questions and carry 1 mark
each.
3. Questions number 6 to 10 are short answer questions and carry 2 mark each.
4. Questions number 11 to 22 are also short answer questions and carry 3 marks
each.
5. Questions number 23 is values based and carry 4 marks.
6. Question number 24 to 26 are of long answer questions and carry 5 marks
each.
7. Use Log tables, if necessary. Use of calculator is not allowed.
8. There is no overall choice in the paper; however there is an internal choice in
onequestion of 2 marks weightage, one question of 3 mark weightage
and all questions of5 marks weightage.
1 / State Charle’s Law. / 1
2 / Name two medicines used in treatment of cancer. / 1
3 / State First Law of Thermodynamics. / 1
4 / Write IUPAC name of the following compound-
(CH3) 2CHCH(OH)CH2CHO / 1
5 / Draw structure of BeCl2 in solid state. / 1
6 / Calcium carbonate reacts with aqueous of HCl according to the reaction
CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + CO2 (g) +H2O (l)
What mass of CaCO3is required to react completely with 25 ml of 0.75 M HCl. / 2
7 / (a) Define molality.
(b) State law of constant proportions.
OR
(a) How many significant figures are in the following?
(i) 0.00200 (ii) 40000
(b) Define mole fraction. / 2
8 / Observe the following species - Mg2+ , O2-, Al3+ , Na+, Ne
(a) What is common between these species?
(b) Arrange them in their increasing order of size. / 2
9 / (a) The element with atomic number 116 has not been discovered.
What could be its IUPAC name and symbol?
(b) Out of sulphur and oxygen which has more negative electron
gain enthalpy and why? / 2
10 / On the basis of MOT magnetic nature of dioxygen. / 2
11 / (a) Draw resonating structures of phenol.
(b) Define electrophile.
(c) Name a method for separation of glycerol from spent lye of
soap industry. / 3
12 / (a) Write short note on the following with suitable example-
(i) Metamerism (ii) Hyper conjugation
(b) Explain the reason for the fusion of an organic compound with
sodium metal for testing of nitrogen, halogen and sulphur. / 3
13 / Pressure of 1 g of an ideal gas A at 270C is found to be 2 bar. When 2 g of another ideal gas B is introduced in the same flask at same temperature, the pressure becomes 3 bar. Find the relationship between their molecular masses. / 3
14 / (a) Derive relationship between KP and KC .
(b) State Henry’s law.
OR
(a) State Le- chatelier’s principle. Write its application in
manufacture of ammonia by Haber’s process.
(b) What is heterogeneous equilibrium? / 3
15 / (a) Predict hybridization and shape of the following molecules-
PCl5 , SF4
(b) Explain, why sigma bond is stronger than pi bond? / 3
16 / (a) The velocity associated with a proton moving in a potential
difference of 1000 V is 4.37 x 105 ms-1 . if a hockey ball of mass
0.1 kg is moving with this speed, calculate the wavelength
associated with this velocity.
(b) Explain uncertainty principle. / 3
17 / (a) Draw geometrical isomers of But-2-ene and compare their
stability.
(b) How will you convert ethyne into benzene? / 3
18 / (a) State Pauli’s exclusion principle.
(b) What is the maximum number of emission lines obtained when the
excited electron of a Hydrogen atom in n = 6 drops to the ground
state?
(c) Write electronic configuration of Cr (Z= 24). / 3
19 / (a) The degree of ionization of a 0.1 M bromoacetic acid solution is
0.132. Calculate pH of the solution.
(b) Explain common ion effect with the help of one suitable example. / 3
20 / Dichromate ion (Cr2O72- )in aqueous acidic medium reacts with ferrous ion (Fe2+) to give ferric ion (Fe3+) and chromium ions (Cr3+). Write balanced chemical equation for the reaction. (Balance the equation by any method) / 3
21 / (a) Why density of ice is lower than that of water?
(b) Write short note on water gas shift reaction?
(c) Why H2O2 stored in wax line glass bottles or plastic bottles? / 3
22 / (a) How photo chemical smog is different from classical smog?
(b) Name two gases responsible for green house effect.
(c) Define Biological Oxygen Demand of the water? / 3
23 / Lewis mother was making cake for his birth day party, but the cake prepared was hard and it was not spongy. Mother tried again, this time Lewis suggested his mother to add a chemical substance while making the cake. This time cake formed was soft and spongy.
(a) Name the substance suggested by Lewis.
(b) Why the cake become soft and spongy on addition of the
substance. Explain with suitable chemical reaction.
(c) What values are shown by Lewis? / 4
24 / (a) State Hess Law.
(b) Define state function.
(c) The combustion of one mole of benzene takes place at 298 K and
1 atm. After combustion CO2 (g) and H2O (l) are produced and
3267.0 KJ of heat is librated. Calculate standard enthalpy of
formation of benzene. The standard enthalpies of formation of CO2
(g) and H2O (l) are – 393.5 KJ mol-1 and -285.83 KJ mol-1
respectively.
OR
(a) Define entropy.
(b) What is adiabatic process?
(c) For the reaction 2A(g) + B (g) → 2D (g),
∆ Uo = - 10.5 KJ and ∆ So = - 44.10 JK-1
Calculate ∆Go for the reaction and predict whether the reaction is
spontaneous or not. / 5
25 / (a) Write short note on the following-
(i) Wurtz reaction (ii) Frediel craft reaction
(b) Complete the following reactions-
(i) CaC2 + H2O →
(ii) CH3-CH=CH2 + HBr →
(iii) CH3CH2COOH + NaOH (CaO) →
OR
(a) Write balanced chemical equations for the following reactions-
(i) But-2-ene treated with ozone followed by reaction with zincdust.
(ii) Propene reacted with water in presence of sulphuric acid.
(iii) Benzene treated with n-propyl chloride in presence of AlCl3.
(b) Write short note on- (i) Kolbe electrolysis
(c) Draw Newman projection formula of all conformations of C2H6. / 5
26 / (a) What is inorganic benzene and why is it so called?
(b) Account for the following with the help of suitable chemical
equation-
(i) Aqueous solution of borax (Na2B4O7) is alkaline in nature.
(ii) Carbon monoxide is a good reducing agent.
(c) Compare structure of diamond and graphite.
OR
(a) What are silicones? How silicones can be prepared? Write
balanced chemical equations for the reactions involved.
(b) Explain structure of diborane. / 5