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#### Term 1 Model Question Paper

11th Standard

Reg.No. :
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Chemistry

Time : 02:00:00 Hrs
Total Marks : 60
8 x 1 = 8
1. An element X has the following isotopic Composition 200X = 90%, 199X = 8% and 202X = 2% The Weighted average atomic mass of the element X is closet to

(a)

201 u

(b)

202 u

(c)

199 u

(d)

200 u

2. The characteristic feature of orderly arrangement of molecules belongs to

(a)

Solids

(b)

Liquid

(c)

Gases

(d)

None of these

3. The maximum number of electrons in a sub shell is given by the expression

(a)

2n2

(b)

21+ I

(c)

41+ 2

(d)

none of these

4. The correct order of electron gain enthalpy with negative sign of F, Cl, Br and I having atomic number 9, 17, 35 and 53 respectively is

(a)

I > Br > Cl > F

(b)

F > Cl > Br > I

(c)

Cl > F > Br > I

(d)

Br > I > Cl > F

5. The correct order of decreasing electronegativity values among the elements X, Y, Z and A with atomic numbers 4, 8, 7 and 12 respectively

(a)

Y > Z > X > A

(b)

Z > A > Y > X

(c)

X > Y > Z > A

(d)

X > Y > A > Z

6. Tritium nucleus contains

(a)

1 p+0 n

(b)

2 p+1 n

(c)

1 p + 2 n

(d)

none of these

7. RbO2 is

(a)

superoxide and paramagnetic

(b)

peroxide and diamagnetic

(c)

superoxide and diamagnetic

(d)

peroxide and paramagnetic

8. The value of the gas constant R is

(a)

0.082 dm2 atm.

(b)

0.987 cal mol-1K-1

(c)

8.3 J mol-1 K-1

(d)

8 erg mol-1 K-1

9. 7 x 2 = 14
10. Distinguish between oxidation and reduction.

11. For each of the following, give the sub level designation, the allowable m values and the number of orbitals
(i) n = 4, 1=2, (ii) n = 5, 1=3 (iii) n = 7, 1=0

12. Define modern periodic law.

13. Discuss the three types of Covalent hydrides.

14. How is plaster of paris prepared?

15. Distinguish between diffusion and effusion.

16. State the first law of thermodynamics.

17. 6 x 3 = 18
18. How many moles of ethane is required to produce 44 g of CO2(g) after combustion

19. Describe the Autbau principle

20. Mention any two anomalous properties of second period elements.

21. Give the uses of heavy water,

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

23. What are state and path functions? Give two examples

24. 4 x 5 = 20
25. The reaction between aluminum and ferric oxide can generate temperatures up to 3273 K and is used in welding metals. (Atomic mass of AC = 27 u atomic mass of O = 16 u )
2Al + Fe2O3 $\longrightarrow$ Al2O3 + 2Fe;  If in this process, 324 g of aluminum is allowed to react with 1.12 kg of ferric oxide
i) Calculate the mass of Al2O3 formed
ii) How much of the excess reagent is left at the end of the reaction?

26. Explain the diagonal relationship.

27. List the characteristics of internal energy.

28. A gas mixture of 3.67 lit of ethylene and methane on complete combustion at 25°C and at 1 atm pressure produce 6.11 lit of carbondioxide. Find out the amount of heat evolved in kJ, during this combustion. (ΔHc(CH4)= - 890 kJ mol-1 and (ΔHc(C2H4) = -1423 kJ mol-1