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#### Plus One Official Public Model Question 2019

11th Standard

Reg.No. :
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Chemistry

Time : 02:30:00 Hrs
Total Marks : 70
15 x 1 = 15
1. The change in the oxidation number of S in H2S and SO2,in the following industrial reaction:
2H2S(g) + SO2(g) $\longrightarrow$ 3S(s) + H2O(g)

(a)

-2 to 0, +4 to 0

(b)

-2 to 0, +4 to -1

(c)

-2 to -1, +4 to 0

(d)

-2 to -1, +4 to -2

2. Time independent Schnodinger wave equation is

(a)

$\overset { \wedge }{ H } \psi =E\psi$

(b)

${ \triangledown }^{ 2 }\psi +\frac { 8{ \pi }^{ 2 }m }{ { h }^{ 2 } } (E+V)\psi =0$

(c)

$\frac { { \partial }^{ 2 }\psi }{ { \partial x }^{ 2 } } +\frac { { \partial }^{ 2 }\psi }{ { \partial y }^{ 2 } } +\frac { { \partial }^{ 2 }\psi }{ { \partial z }^{ 2 } } +\frac { { 2m } }{ { h }^{ 2 } } (E-V)\Psi =0$

(d)

All of these

3. Match the list I with list II and select the correct answer using the code given below the list.

 List I List II A Ionisation energy 1 ionic compound B electro negativity 2 alloys C s-block elements 3 KJ mol-1 D d-block elements 4 No unit
(a)
 A B C D 1 2 3 4
(b)
 A B C D 3 2 1 4
(c)
 A B C D 2 3 1 4
(d)
 A B C D 3 4 1 2
4. The reaction H3PO2 + D2O ➝ H2DPO2 + HDO indicates that hypo-phosphorus acid is

(a)

tribasic acid

(b)

dibasic acid

(c)

mono basic acid

(d)

none of these

5. A colourless solid substance (A) on heating evolved CO2 and also gave a white residue, soluble in water. Residue also gave CO2 when treated with dilute HCI

(a)

Na2CO3

(b)

NaHCO3

(c)

CaCO3

(d)

Ca(HCO3)2

6. 25g of each of the following gases are taken at 27°C and 600 mm Hg pressure. Which of these will have the least volume?

(a)

HBr

(b)

HCI

(c)

HF

(d)

HI

7. Given that C(g)+ O2(g) ⟶ CO2(g)ΔHo =-akJ;2CO(g)+O2(g) ⟶ 2CO2(g)ΔHo=-bkJ; Calculate the AHo for the reaction C(g)+ 1/2O2(g) ⟶ CO(g)

(a)

$\frac{b+2a}{2}$

(b)

2a-b

(c)

$\frac{2a-b}{2}$

(d)

$\frac{b-2a}{2}$

8. Two moles of N2 and two moles of H2 are taken in a closed vessel of 5 litre capacity and suitable conditions are provided for the reaction. When the equilibrium is reached, it is found that a half mole of N2 is used up. The equilibrium concentration of NH3 is

(a)

0.2

(b)

0.4

(c)

0.3.

(d)

0.1

9. Normality of 1.25M sulphuric acid is

(a)

1.25 N

(b)

3.75 N

(c)

2.5 N

(d)

2.25 N

10. The molecule that has linear structure is

(a)

CO2

(b)

NO2

(c)

SO2

(d)

SiO2

11. The general formula for alkadiene is

(a)

CnH2n

(b)

CnH2n-1

(c)

CnH2n-2

(d)

CnHn-2

12. -I effect is shown by

(a)

-Cl

(b)

-Br

(c)

both (a) and (b)

(d)

-CH3

13. Which of the following is the most reactive towards electrophilic substitution reaction?

(a)

(b)

(c)

(d)

14. ___________is used in fire extinguishers

(a)

CCl2 = CCl2

(b)

CHCl = CCl2

(c)

CH2 = CCl2

(d)

CCl4

15. Identify the wrong statement in the following

(a)

The clean water would have a BOD value of more than 5 ppm

(b)

Greenhouse effect is also called as Global warming

(c)

Minute solid particles in air is known as particulate pollutants

(d)

Biosphere is the protective blanket of gases surrounding the earth

16. 6 x 2 = 12
17. If 10 volumes of H2 gas react with 5 volumes of O2 gas, how many volumes of water vapour would be produced?

18. Which quantum number reveal information about the shape, energy, orientation and size of orbitals?

19. Show by chemical reaction, with water, that Na2O is a basic oxide and Cl2O7 is an acidic oxide

20. State Avogadro's hypothesis.

21. Deduce the Vant Hoff equation.

22. Consider the molecules NH2-, NH3, NH4+. Arrange them in the decreasing order of bond angles and give reason for your arrangement.

23. What is meant by a functional group? Identify the functional group in the following compounds.
(a) acetaldehyde
(b) oxalic acid
(c) di methyl ether
(d) methylamine

24. Identify the electrophilic centre in the following compound & CH3 - CH = O, CH3CN, CH3I.

25. Write short notes on the the following
i) Raschig process
ii) Dows Process
iii) Darzens process

26. 6 x 3 = 18
27. What is the empirical formula of the following?
i) Fructose (C6 H12O6) Found in honey
ii) Caffeine  (C8H10N4 O2) a substance found in tea and Coffee

28. Which of the following pairs of elements would have more negative electron gain enthalpy? (I) O or F(ii) For Cl.

29. What is water-gas shift reaction?

30. Argon is an inert gas used in light bulbs to retard the vaporization of the tungsten filament. A certain light bulb containing argon at 1.2 atm and 18°C is heated to 85°C at constant volume. Calculate its final pressure in atm.

31. Define the following terms.

32. 0.2 m aqueous solution of KCl freezes at -0.68ºC calculate van’t Hoff factor. kf for water is 1.86 K kg mol-1.

33. Which among the following hybrid orbitals are highly electronegative? sp, sp2 , sp3 .

34. Write a note on the following reactions.
(i) Dehydration of ethanol
(ii) Electrolysis of potassium succinate
(iii) Chlorination of ethene

35. On the basis of chemical reactions involved, explain how do CFC’s cause depletion of ozone layer in stratosphere?

36. 5 x 5 = 25
37. Calculate the percentage composition of the elements present in magnesium carbonate. How many Kg of CO2 can be obtained from 100 Kg of is 90% pure magnesium carbonate.

38. Why the first ionisation enthalpy of sodium is lower than that of magnesium while its second ionisation enthalpy is higher than that of magnesium.

39. Conc. H2SO4 cannot be used for drying hydrogen gas. Why?

40. Describe briefly the biological Importance of Calcium and magnesium

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

Experiment Volume (L) Temperature (0C)
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?

42. Explain how heat absorbed at constant volume is measured using bomb calorimeter with a neat diagram.

43. 1 mol of PCl5, kept in a closed container of volume 1 dm3 and was allowed to attain equilibrium at 423 K. Calculate the equilibrium composition of reaction mixture. (The Kc value for PCl5 dissociation at 423 K is 2)

44. Explain the estimation of carbon and hydrogen present in an organic compound.

45. How will you convert t-butyl bromide into t-butyl alcohol? Explain the process through the mechanism in stepwise manner.

46. How does classical smog differ from photochemical smog?