#### Model Question Paper Part III

11th Standard

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Chemistry

Time : 02:30:00 Hrs
Total Marks : 100

Part I

Choose the most suitable answer from the given four alternatives and write the option code with the corresponding answer.

15 x 1 = 15
1. Identify the correct statement(s) with respect to the following reaction :
Zn + 2HCl $\longrightarrow$ ZnCl2 + H2
(i) Zinc is acting as an oxidant
(ii) Chlorine is acting as a reductant
(iii) Hydrogen is not acting as an oxidant
(iv) Zn is acting as a reductant

(a)

only (ii)

(b)

only (iv)

(c)

both (ii) and (iii)

(d)

both (ii) and (i)

2. A macroscopic particle of mass 100 g and moving at a velocity of 100 cm S-1 will have a de Broglie wavelength of

(a)

6.6 x 10-29 em

(b)

6.6 x 10-30 em

(c)

6.6 x 10-31 em

(d)

6.6 x 10-32 em

3. On moving from left to right across a period in the periodic table, the metallic character__________.

(a)

increases

(b)

decreases

(c)

remains constant

(d)

first increases and then decreases

4. Zeolite used to soften hardness of water is hydrated

(a)

Sodium aluminium silicate

(b)

Calcium aluminium silicate

(c)

Zinc aluminium borate

(d)

Lithium aluminium hydride

5. Which one of the following is known as natural insulator?

(a)

FeSO4·7H2O

(b)

Na2CO310H2O

(c)

CaSO4.2H2O

(d)

CaSO4.1/2H2O

6. Which of the following gas is essential for our survival?

(a)

N2

(b)

H2

(c)

O2

(d)

He

7. The heat of formation of CO and CO2 are - 26.4 kcal and - 94 kcal, respectively. Heat of combustion of carbon monoxide will be

(a)

+ 26.4 kcal

(b)

- 67.6 kcal

(c)

- 120.6 kcal

(d)

+ 52.8 kcal

8. The formation of ammonia from N2(g) and H2(g) is a reversible reaction
N2(g) + 3H2(g) ⇌ 2NH3(g) + Heat
What is the effect of increase of temperature on this equilibrium reaction

(a)

equilibrium is unaltered

(b)

formation of ammonia is favoured

(c)

equilibrium is shifted to the left

(d)

reaction rate does not change

9. Which one of the following binary liquid mixtures exhibits positive deviation from Raoults law?

(a)

Acetone + chloroform

(b)

Water + nitric acid

(c)

HCl + water

(d)

ethanol + water

10. The shape of IF7 molecule is

(a)

square planar

(b)

tetrahedral

(c)

Pentagonal bipyramidal

(d)

linear

11. The IUPAC name of the compound CH– CH = CH – C ≡ CH is

(a)

Pent - 4 - yn-2-ene

(b)

Pent -3-en-l-yne

(c)

pent – 2– en – 4 – yne

(d)

Pent – 1 – yn –3 –ene

(a)

Benzoyl peroxide

(b)

Benzyl alcohol

(c)

Benzyl acetate

(d)

Benzaldehyde.

13. Conformation arise due to rotation around

(a)

Carbon-carbon double bond

(b)

Carbon-carbon triple bond

(c)

Carbon-carbon single bond

(d)

All of these

14. In SN1, the rate of the reaction depends on the ______________.

(a)

nucleophile

(b)

medium

(c)

concentration of the substrate

(d)

none of the above

15. Assertion (A): Excessive use of chlorinated pesticide causes soil and water pollution.
Reason (R) : Such pesticides are non-biodegradable.

(a)

Both (A) and R are correct and (R) is the correct explanation of (A)

(b)

Both (A) and R are correct and (R) is not the correct explanation of (A)

(c)

Both (A) and R are not correct

(d)

(A) is correct but( R) is not correct

16. Part II

Answer any 6 questions. Question no. 24 is compulsory.

6 x 2 = 12
17. Calculate the equivalent mass of the following:CO3-2,

18. How many radial nodes for 2s, 4p, 5d and 4f orbitals exhibit? How many angular nodes

19. Explain what is meant by efflerescence.

20. Define rate of diffusion

21. What are the scope of thermodynamics?

22. Deduce the Vant Hoff equation.

23. Draw the lewis structure of PCl5 and SF6

24. Describe the classification of organic compounds based on their structure.

25. What are Freons? Discuss their uses and environmental effects

26. Part III

Answer any 6 questions. Question no. 33 is compulsory.

6 x 3 = 18
27. Calculate the number of atoms / molecules present in the following 1.8 gram of water

28. The quantum mechanical treatment of the hydrogen atom gives the energy value:
${ E }_{ n }=\frac { -13.6 }{ { n }_{ 2 } } ev{ \quad atom }^{ -1 }$
(i) use this expression to find AE between n = 3 andm=4
(ii) Calculate the wavelength corresponding to the above transition.

29. In what period and group will an element with Z = 118 will be present?

30. What is hydrogen bonding?

31. Write balanced chemical equation for each of the following chemical reactions.
(i) Lithium metal with nitrogen gas
(ii) heating solid sodium bicarbonate
(iii) Rubidum with oxgen gas
(iv) solid potassium hydroxide with CO2
(v) heating calcium carbonate
(vi) heating calcium with oxygen

32. Explain the graphical representation of Boyle's law.

33. The equilibrium constant of a reaction is 10, what will be the sign of ΔG? Will this reaction be spontaneous?

34. Vapour pressure of a pure liquid A is 10.0 torr at 27°C. The vapour pressure is lowered to 9.0 torr on dissolving one gram of B in 20 g of A. If the molar mass of A is 200 then calculate the molar mass of B.

35. Which bond is more polar in the following pair of molecular?
(i) H3C-H (or) H3C-Br
(ii) H3C-NH2 (or) H3C-OH
(iii) H3C-OH (or) H3C-SH

36. Part IV

5 x 5 = 25
37. Balance the following equations by oxidation number method.
CuO + NH3 ⟶ Cu +N2 + H2O

38. Calculate the de Broglie wavelength of an electron that has been accelerated from rest through 1potential differences of 1 KV.

39. I.E increases as we move across the period but Ionisation enthalpies (I.E) of second period of elements in the order.
Li < B < Be < C < O < N < F < Ne
Explain why?
(i) Be has higher I.E and B
(ii) O has lower I.E than N & F

40. A group metal (A) which is present in common salt reacts with (B) to give compound (C) in which hydrogen is present in -1 oxidation state. (B) on reaction with a gas -gives universal solvent (D). The compound (D) reacts with (A) to give (E), a strong base. Identify A, B, C, D and E. Explain the reactions.

41. Distinguish between alkali metals and alkaline earth metals.

42. The enthalpy of combustion for H2, C(graphite) and CH4 are -285.8, -393.5 and -890.4 kJ mol-1respectively. Calculate the standard enthalpy of formation $\Delta { H }_{ f }^{ 0 }$ for CH4

43. Explain about the salient features of molecular orbital theory.

44. Identify the compound A, B, C and D in the following series of reactions

Write short notes on ortho, para directors in aromatic electrophilic substitution reactions.

45. The simplest aromatic hydrocarbon C6H6 reactsⒷ on treatment with sodium hydroxide will (C6H5OH), Phenol, © as the product. Also Cl2 to giveⒶ which on reaction with sodium hydroxide gives Ⓑ.Ⓑ of molecular formula C6H6O. @ on treatment with ammonia will give C6H7N as @. Identify Ⓐ, Ⓑ, ©, and explain the reactions involved.

46. Ethane burns completely in air to give CO2, while in a limited supply of air gives CO. The same gases are found in automobile exhaust. Both CO and CO2 are atmospheric pollutants
i) What is the danger associated with these gases
ii) How do the pollutants affect the human body?