#### Half Yearly Model Question Paper 2019

11th Standard

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Chemistry

Time : 02:30:00 Hrs
Total Marks : 70

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. 40 ml of methane is completely burnt using 80 ml of oxygen at room temperature The volume of gas left. after cooling to room temperature is

(a)

40 ml CO2 gas

(b)

40 ml CO2 gas and 80 ml H2O gas

(c)

60 ml CO2 gas and 60 ml H2O gas

(d)

120 ml CO2 gas

2. Two electrons occupying the same orbital are distinguished by

(a)

azimuthal quantum number

(b)

spin quantum number

(c)

magnetic quantum number

(d)

orbital quantum number

3. Law of triad was unable to explain for the element

(a)

Ca, Sr and Ba

(b)

Fe, Co, Ni

(c)

Li, Na, K

(d)

CI, Br, I

4. Heavy water is used as

(a)

moderator in nuclear reactions

(b)

coolant in nuclear reactions

(c)

both (a) and (b)

(d)

none of these

5. The suspension of slaked lime in water is known as

(a)

lime water

(b)

quick lime

(c)

milk of lime

(d)

aqueous solution of slaked lime

6. The ideal gas equation is ____________.

(a)

PV = RT for 1 mole

(b)

P1V1 = P2V2

(c)

$\frac{P}{T}=R$

(d)

P = P1 + P2 + P3

7. An ideal gas expands from the volume of 1 x 10-3 m3 to 1 x 10-2 m3 at 300 K against a constant pressure at 1 x 105 Nm-2. The work done is

(a)

- 900 J

(b)

900 kJ

(c)

270 kJ

(d)

-900 kJ

8. Solubility of carbon dioxide gas in cold water can be increased by

(a)

increase in pressure

(b)

decrease in pressure

(c)

increase in volume

(d)

none of these

9. The KH for the solution of oxygen dissolved in water is 4 × 104 atm at a given temperature. If the partial pressure of oxygen in air is 0.4 atm, the mole fraction of oxygen in solution is

(a)

4.6 x 103

(b)

1.6 x 104

(c)

1 x 10-5

(d)

1 x 105

10. Which one of the following names does not fit a real name?

(a)

3 – Methyl –3–hexanone

(b)

4–Methyl –3– hexanone

(c)

3– Methyl –3– hexanol

(d)

2– Methyl cyclo hexanone

11. Identify the colour formed in the test for phosphorous using ammonium molybdate.

(a)

Crimson red colour

(b)

Deep violet colour

(c)

Prussian blue colour

(d)

Canary yellow colour

12. The geometrical shape of carbocation is

(a)

Linear

(b)

tetrahedral

(c)

Planar

(d)

Pyramidal

13. Peroxide effect (Kharasch effect) can be studied in case of

(a)

Oct – 4 – ene

(b)

hex – 3 – ene

(c)

pent – 1 – ene

(d)

but – 2 – ene

14. Which of the following is the most stable cycloalkane?

(a)

(b)

(c)

(d)

15. Which of the following compounds will give racemic mixture on nucleophilic substitution by OH- ion?

(a)

(i)

(b)

(ii) and (iii)

(c)

(iii)

(d)

(i) and (ii)

16. Part II

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

6 x 2 = 12
17. Calculate the molar mass of the following compounds. - acetone [CH3 COCH3]

18. After the execution of the $\alpha$-ray scattering experiment, what were the observations made by Rutherford? What did he conclude from his observations?

19. Name the first and the last elements in the following periods (n) .(i) n=:4 (ii) n = 5 (iii) n = 6 (iv) n = 7

20. Write short notes on Deuterium.

21. Why alkaline earth metals are harder than alkali metals.

22. Distinguish between diffusion and effusion.

23. Explain intensive properties with two examples

24. A 0.25 M glucose solution at 370.28 K has approximately the pressure as blood does what is the osmotic pressure of blood?

25. What is Grignard reagent? How is it prepared from ethyl bromide?

26. Part III

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

6 x 3 = 18
27. How much volume of chlorine is required to form 11.2 L of HCI at 273 K and 1 atm pressure?

28. Using Aufbau principle, write the ground state electronic configuration of following atoms.
(i) Boron (Z = 5)
(ii) Neon (Z = 10)
(iii) Aluminium (Z = 13)
(iv) Chlorine (Z = 17)
(v) Calcium (Z = 20)
(vi) Rubidium (Z = 37)

29. Noble gases have maximum ionisation energy. Justify.

30. Why sodium hydroxide is much more water soluble than chloride?

31. Would it be easier to drink water with a straw on the top of Mount Everest?

32. Identify processes under the following conditions
(i) dT = 0 (ii) dP = 0 (iii) dV = 0

33. The value of Kc for the reaction

34. 0.16 g of an organic compound was heated in a carius tube and H2SO4 acid formed was precipitated with BaCl2. The mass of BaSO4 was 0.35g. Find the percentage of sulphur [30.04]

35. Write the equations for the preparation of l-iodobutane from.

36. Part IV

5 x 5 = 25
1. Explain electron movement in organic reactions.

2. What happens when propene is treated with the following.
(i) H2SO4
(ii) Ozone
(iii) HBr
(iv) Red hot Fe tube
(v) Acidified KMnO4

1. Suggest and explain an indirect method to calculate lattice enthalpy of sodium chloride crystal

2. Explain the positive deviation exhibited by nonideal solutions with preference to a solution of ethyl alcohol and water

1. Dihydrogen reacts with dioxygen (O2) to form water. Write the name and formula of the product when the isotope of hydrogen which has one proton and one neutron in its nucleus is treated with oxygen. Will the reactivity of both the isotopes be the same towards oxygen? Justify your answer.

2. In an experimant of verification of Charle's law, the following are the set of readings taken by a student

 Experiment Volume (L) Temperature (°C) 1 1.54 20 2 1.65 40 3 1.95 100 4 2.07 120

What is the average value of the constant of proportionality?

1. By using paulings method calculate the ionic radii of K+ and CI- ions in the potassium chloride crystal. Given that dk+-cl-=3.14 Å.

2. Give the uses of gypsum

1. A laboratory analysis of an organic compound gives the following mass percentage composition: C = 60%, H = 4.48% and remaining oxygen.

2. What is the de Broglie wavelength (in cm) of a 160g cricket ball travelling at 140 Km hr-1.