MODEL PAPER

1. NAVODAYA VIDYALAYA SAMITI,
CHEMISTRY REVISION PAPER - I
THE SOLID STATE AND CHEMICAL KINETICS
Class : XII Max. Marks: 70
Time : 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 solids
7. 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 10-3
mol L-1
s-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 of
the compound?
13. How will you distinguish between
a) Tetrahedral void and octahedral void
b) 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-1
mol-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 1/16th
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?
K.G.MALLIKARJUN,JNV,ANANTHAPUR
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2. 20. The rate constant of a reaction at 700K and 760K are 0.011M-1
s-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/min
1 0.1 0.1 2.0 x 10-2
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. Ferrimagnetism
24. (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 Si
27. 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
K.G.MALLIKARJUN,JNV,ANANTHAPUR
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3. 1. 0.30 0.30 0.096
2. 0.60 0.30 0.384
3. 0.30 0.60 0.192
4. 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/atm
01 0 0.5
02 100 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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