NAVODAYA VIDYALAYA SAMITI, CHEMISTRY REVISION PAPER - I

THE SOLID STATE AND CHEMICAL KINETICS

Class : XII Max. Marks: 70Time : 3hrs.

General Instructions:(i) All questions are compulsory.(ii) Marks for each question are indicated against it.(iii) Q.No.1and 8carrying 1 mark each.(iv) Q.No.9to 18 carrying 2 marks each.(v) Q.No.19 to 27 carrying 3 marks each(vi) Q.No. 28 to 30carrying 5 marks each(vii) Use log Tables, if necessary, Use of calculators is not

permitted.

Answer the following questions:

1. What type of stoichiometric defect is shown by ZnS and AgBr.2. When do you say the rate constant is the specific rate constant?3. On heating crystals of KCl in potassium vapours, the crystal start exhibiting a violet colour, why?4. Differentiate between schottky and Frenkel defect?5. Solid solution of group 13 or 15 group impurities with group 14 elements            are found to exhibit unusual electric properties. Why?6. Give exact differences between anisotropic and isotropic solids7. Calculate the half-life period of a first order reaction whose rate constant is 200 S-1?8. The specific rate of reaction is 4.2 x 10-3mol L-1s-1, what is order of reaction?9. Analysis shows that nickel oxide has formula Ni0.98 O1..00. What fractions of the nickel exist as Ni+2 and Ni+3 ions.10. Classify each by bonding or attractive forces in the following : 1. ZnS . 2. HCl 3. SiC and 4. CCl4

11. What is by (i) 12-16 compounds and (ii) 13-15 compound? Give example.12. A compound is found by A and B. B particles are anions make CCP

Where as particles A occupy all octahedral voids. Give the formula ofthe compound?

13. How will you distinguish betweena) Tetrahedral void and octahedral voidb) Hexagonal close packing and cubic close - packing

14. Calculate the value of activation energy, if rate of reaction doubles when           rise in temperature from 295Kto 305K takes place?(R = 8.314 JK-

1mol-1

15. The rate constant for a first order reaction is 60s -1. How much time will it take to reduce the initial concentration of the reactant to its 1/16 th

value?16. Mention the factors that affect the rate of a chemical reaction?17. What is meant by order and molecularity of a reaction? Distinguish between order and molecularity?18. What is the effect of catalyst on activation energy? Show by graphical representation?19. (a) A first order reaction is 15% completed in 20min. How long will it take                to complete 60%?

(b) What is the significance of rate constant in a rate law?20. The rate constant of a reaction at 700K and 760K are 0.011M -1s-1 and 0.105 M -1 s -1 respectively. Calculate the values of Arrhenius parameters (Ea and A).21. The reaction between A and B is first order with respective to A and

zero order with respect to B. Fill in the blank in the following table.

Experiment{A]

mol .[B]

mol.Initial rate /

mol/min1 0.1 0.1 2.0 x 10-2

K.G.MALLIKARJUN,JNV,ANANTHAPUR

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2 --- 0.2 4.0 x 10-2

3. 0.4 0.4 ------

4 --- 0.2 2.0 x 10-2

22. A reaction is first order in A and second order in B.(i) Write differential rate equation(ii) How is the rate affected when the concentration of B is tripled?(iii) How is the rate affected when the concentration of both A and B is

doubled?23. Answer the following with suitable examples. 1. Ferromagnetic

2. Antiferromagnetic 3. Ferrimagnetism24. (a) For the reaction at 500K

NO2(g) + CO(g) CO2 (g) + NO(g) the proposed mechanism is as below: (i) NO2 + NO2 NO + NO3 (Slow) (ii) NO3 + CO CO2 + NO2 (Fast)

what is the rate law for the reaction?(b) For the reaction A + B → Product: the rate law is given by,

r = k [A]1/2 [B]2 . What is the order of the reaction?25. (a). Define the term ‘Amorphous’. Give a few examples of amorphous solids?

(b) What are the coordination numbers of Ca+2 and F- ions in CaF2

structure?26. (i). Calculate the efficiency of packing of body centred cubic   structure

(ii). Classify each of the following as being either a p-type or n-type semiconductors (a) Ge doped with In (b) B doped with Si27. An element has a body-centered cubic structure with a cell edge of 200pm .The density of the element is 7.2g/cm3

. How many atoms are present in 200g of the element?28. (a). In terms of band theory, what is the difference (i) Between a conductor and an insulator (ii) Between a condor and a semiconductor?

(b). Niobium crystallizes in body centred cubic structure. If the density is 8.55 g/cm3 Calculate the atomic radius of niobium using its atomic mass 93u.29. (a). Give an example of a pseudo first order reaction?

(b) Explain temperature coefficient?( c ) In the reaction 2NO(g)+ O2(g) -----2NO2(g)

Calculate order of NO and O2 and find the rate constant K using the given data?

Experiment

Initial[NO] mol/L Initial [O2] mol/L Initial rate NO2 mol/L/sec

1. 0.30 0.30 0.0962. 0.60 0.30 0.3843. 0.30 0.60 0.1924. 0.60 0.60 0.768

30. (a). The following data were obtained during the first order thermal            decomposition of SO2Cl2 at a constant volume.            SO2Cl2 (g) → SO2(g) + Cl2(g)

Experiment Time/sec. Total pressure/atm01 0 0.502 100 0.6

              Calculate the rate of the reaction when total pressure is 0.65atm(b) What is the effect of temperature on the rate constant of a

reaction? How this temperature effect on rate constant be                 represented quantitatively?

K.G.MALLIKARJUN,JNV,ANANTHAPUR

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K.G.MALLIKARJUN,JNV,ANANTHAPUR

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