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Board : Tripura Board Of Secondary Education
Exam : Class XI
Subject : Chemistry
Document Type : Sample Question Paper
Website : tbse.nic.in

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/7280-Chemistry.pdf

TBSE Chemistry Question Paper

Chemistry :
Class- XI :
(Theory)

Related : Tripura Board Of Secondary Education Class XI Physics Question Paper : www.pdfquestion.in/7281.html

Time : 3 Hrs. Maximum Marks : 70
General Instructions :
a) All the questions are compulsory.
b) There are 30 questions in total.
c) Questions 1 to 8 are very short answer type questions and carry one mark each.
d) Questions 9 to 18 carry two marks each.
e) Questions 19 to 27 carry three marks each.
f) Questions 28 to 30 carry five marks each.
g) There is no overall choice. However, an internal choice has been provided in one question of two marks, one question of three marks and all three questions of five marks each. You have to attempt only one of the choices in such questions.
h) Use of calculators is not permitted. However, you may use log tables if necessary.

SAMPLE QUESTION PAPER :

Group- A

1. O2-, Na+, Mg2+, AI3+
Arrange the following species in order of increasing ionic radii.
O2-, Na+, Mg2, Al3+

2. NH4
Write the state of hybridization of nitrogen in NH+

3. Write the mathematical form of first law of thermodynamics.

4. 2H2(g) + O2(g) _ 2H2O(g)
State whether the entropy of the above reaction increases or decreases.

5. What is the pH of 0.001(M) HCI Solution?

6. Give an example of electron deficient hydride.

7. Write the chemical formula of inorganic benzene.

Group- B

9. Calculate the volume of CO2 at STP that can be obtained by heating of 2 Kg of CaCO3.

10 State the Hund’s rule of multiplicity.
ii) 26 Find the number of unpaired electron in the atom of the element having atomic number 26.

11.Which of NH3 and NF3 has higher dipole moment and why ?

12. Derive the relation : PV = nRT (Symbols have their usual meanings).

15. 10 Calculate the strength in g/L of 10 volume of solution of H2O2.

16. K2CO3 can’t be prepared by Solvay’s process. Explain.
17.State with one example each of the following :
i) Wurtz reaction and
ii) Friedel Crafts alkylation reaction.

18. Explain the formation of ozone hole.

Group- C

19. i) State Avogadro law.
ii) Differentiate between molarity and molality.

20. i) Indicate the orbital with the following quantum numbers n=3, I = 1
ii) Calculate the energy associated with the 5th orbital of hydrogen atom if the energy associated with the 1st orbit be 2.17 x 10 -18 J/atom.

21. Explain why
i) Electron affinity of chlorine is greater than that of fluorine.
ii) The size of a cation is smaller than that of the corresponding neutral atom.
iii) The first ionization enthalpy of Be is greater than that of B. But the 2nd ionization enthalpy of Be is less than that of B.

23.
i) Define surface tension
ii) A 2 litre flask contains 0.4 gm of O2 and 0.6 gm of H2 at 373K. Calculate the total pressure of the gas mixture in the flask.

24. i) Define standard enthalpy of formation.
ii) The enthalpy of combustion of methane, graphite and dihydorgen at 298K are – 890.3 KJ/mol, -393.5 KJ/ mol and – 285.5 KJ/ mol respectively. Find the enthalpy of formation of methane.
OR
i) Define entropy.
ii) For the reaction at 298 K, 2A(g) +B(g) _ 2D(g), ??U0 = -10.5 KJ/mol and ??S0 = 44.1JK-1, Calculate

26. i) Draw the structure of BeCl2 in vapour phase.
ii) Write the chemical equation for the preparation of Plaster of Paris.
iii) Why do not Be and Mg give coloured flame?

27. i) Write one chemical test to distinguish between But-2-yne and But-1-yne.
ii) Which one out of -OH and -NO2 is an ortho or para directing group.
iii) An alkene ‘A’ on ozonolysis gives only ethanol, identify A.

Group- D

28.i) Define buffer solution. Give one example of acidic buffer.
ii) What is ionic product of water?
iii) At 25oC solubility product of Mg(OH)2 is 1.4 x 10-11, find its solubility in terms of g/L (Molar mass of Mg (OH)2 = 58
OR
i) State Ostwald’s dilution law and derive its mathematical form.
ii) At 25oC, ionic product of water is 1 x 10-14, find its dissociation constant at the same temperature.

29.i) Na2B4O7 + 2HCl + 5H2O _ ?
ii) Sio2 + NaOH _ ?
(a) Give reasons :
i) Anhydrous AICI3 is covalent but hydrated AICl3 is electrovalent.
ii) Boric acid behaves as Lewis acid.
iii) The +1 oxidation state of thallium is more stable than +3 oxidation state.

(b) Complete the following
i) Na2B4O7 + 2HCl + 5H2O _ ?
ii) SiO2 + NaOH _ ?
OR

c) Give Reason :
i) CO2 is gas but SiO2 is solid at room temperature.
ii) Silicon tetrachloride undergoes hydrolysis but carbon tetrachloride does not.
iii) Concentrated HNO3 can be stored in aluminium container.