IMPORTANT QUESTIONS FOR CLASS XIIth BOARD EXAMINATION
Chemistry part-1
1mark questions
1. What type of stoichiometric defect is shown by ZnS and AgBr?
2. Why glass is considered as super cooled liquid?
3. Why KCl appears pink when heated in K vapors?
4. The electrical conductivity of semiconductors increases with increase in temperature but in case of metals conductivity decreases with rise in temp. Why?
5. In a compound, atoms of Y occupy ccp lattice and those of X occupy 2/3rd of tetrahedral voids. What is the formula of the compound?
6. Two liquids A and B boil at 120 C and 160 C respectively. Which of them has higher vapour pressure at 70 C?
7. What role does the molecular interaction play in the solution of alcohol and water?
8. Define Azeotropes with example.
9. What is the quantity of charge in faraday required to obtain one mole of aluminum from Al2O3?
10. What is the effect of temperature on molar conductivity?
11. Rusting of iron is quicker in saline water than in ordinary water. Why?
12. What is the role of a salt bridge in a galvanic cell?
13. What is the order of reaction whose rate constant has the same units as the rate of reaction?
14. Why rate of reaction does not remain constant throughout?
15. The conversion of molecules X to Y follows second order kinetics.If concentration of X is increased to 3 times how will it affect the rate of formation of Y.
16. What is the use of ZSM-5?
17. What is collodion?
18. Why is it necessary to remove CO when ammonia is obtained by Haber’s process?
19. Mention two ways by which lyophilic colloids can be coagulated.
20. What is Kraft temperature?
21. Bleeding can be stopped by rubbing with alum. Why?
22. Why is silica added to sulphide ore of copper in the reverberatory furnace?
23. Out of C and CO which is a better reducing agent for ZnO?
24. What is the role of cryolite in electrometallurgy of aluminum?
25. Why is CaCO3 added to blast furnace during reduction of Haematite?
26. What is the basic principle involved in zone refining?
27. Arrange NH3 PH3 AsH3 BiH3 SbH3 in the increasing order of basic strength.
28. Why is white phosphorus more reactive than red phosphorus?
29. Arrange F2,Cl2,Br2,I2in the increasing order of bond dissociation energy.
30. Draw the shape of BrF3 on the basis of VSEPR theory.
31. Name a transition element which does not exhibit variable oxidation state.
32. Actinoid contraction is greater than lanthanides contraction,why?
33. Cu+ is unstable in aqueous solution. Why?
34. Why transition metals and their compounds are paramagnetic in nature?
35. Cr2+ is strongly reducing while Mn3+ is strongly oxidizing. Why?
36. What do you understand by ambidentate ligand?
37. What is the difference between homoleptic and heteroleptic complexes?
38. Calculate the magnetic moment of the metal ions present in [Ni(CN)4]2-.
39. Write the formula of Tetraamineaquachloridocobalt(III) chloride.
40. [NiCl4]2- is paramagnetic while [Ni(CO)]4 is diamagnetic though both are tetrahedral. Why?
2marks questions
1. Define the following terms:
a) Isotropy b) Lattice parameters
2. Calculate the packing efficiency of BCC or FCC.
3. Differentiate between Schottky defect and Frenkel defect with example.
4. Explain the following with suitable examples:
(i) Ferrimagnetic substances (ii) 13-15 type semiconductor
5. State Henry’s law and write down its two applications.
6. Why is osmotic pressure considered as a best colligative property to determine the molar mass of an unknown solute?
7. Differentiate between ideal and non-ideal solution with example.
8. Why is the equilibrium constant K, related to only E° cell and not Ecell?
9. Write the cell reaction that occurs in the lead storage battery when the battery is in use.
10. Define (i) Activation energy (ii) Collision frequency
11. Write down the differences between molecularity and order of any reaction.
12. What do you mean by pseudo first order reaction? Give one example.
13. A reaction is first order in A and second order in B.
a) Write differential rate equation b)How is the rate affected on increasing the concentration of B three times?
14. Describe the following types of colloids giving one example for each?
(i)Multi molecular colloids (ii) Macro molecular colloids
15. How does an increase in temperature affect both physical as well as chemical adsorption?
16. Differentiate between electrophoresis and electro-osmosis?
17. Differentiate between chemisorptions and physisorption.
18. Differentiate between: a) flux and slag b) roasting and calcinations
19. Explain the following with suitable reaction:
a) Hydrometallurgy b) Mond’s process
20. The extraction of gold by leaching with NaCN involves both oxidation and reduction. Justify giving equations.
21. What is the role of depressant in froth floatation process? Explain with example.
22. (a) Why is atomic radius of Argon more than that of Chlorine ?
(b) Why is ionization enthalpy of Nitrogen more than oxygen?
23. Explain giving suitable reasons:
(a) NH3 has higher boiling point than PH3
(b) SbF5 is known but BiF5 is unknown
24. Explain giving suitable reasons.
(a) Sulphur in vapour form is paramagnetic in nature.
(b) Catenation properties of Phosphorous is more than Nitrogen.
25. Give chemical equations , when :
(a) Ammonium dichromate is heated?
(b) Sodium azide is heated?
26. Write main differences between the properties of white phosphorus and red phosphorus.
27. (i) Why is ICl more reactive than I2?
(ii) Interhalogen compounds are strong oxidizing agents why?
28. Give chemical reactions for the following observations (i) Inter convertibility of chromate ion and dichromate ion in aqueous solution depends upon pH of the solution (ii) Potassium permanganate is thermally unstable at 513K.
29. Explain the following with respect to transition elements:
(i) high enthalpy of atomization (ii) variable valency
30. Write the state of hybridisation, the shape and the magnetic behavior of the following complexes:
(i) [Co(en)3]Cl3 (ii) [Fe(CN)6]3-
3marks questions
1. What type of defect can arise when solid is heated? Which physical property is affected by it & in what way?
2. State Raoult’s law for a solution containing a non-volatile solute in a volatile solvent and also give its
mathematical expression?
3. Differentiate between molarity and molality for a solution. How does a change in temperature influence their values?
4. What is an electrochemical series? How does it predict the feasibility of a certain redox reaction?
5. Predict the product of electrolysis in each of the following:
a) an aqueous solution of AgNO3 with silver electrodes
b) an aqueous solution of AgNO3 with platinum electrodes
c) a dilute solution of sulphuric acid with platinum electrodes
6. Deduce the integrated rate equation for first order reaction?
7. What do you mean by adsorption isotherm? Explain Freundlich adsorption isotherm.
8. Explain what is observed when:
(i) a beam of light is passed through a colloidal sol
(ii) an electrolyte, say NaCl is added to hydrated ferric oxide sol (iii) electric current is passed through a colloidal sol
9. Explain adsorption theory of heterogeneous catalysis.
10. Explain the reactions taking place inside the blast furnace during extraction of iron.
11. Describe the Hall-Heroult process for extraction of Al from its ore with the help of diagram.
12. Account for the following facts:
(i) Reduction of a metal oxide is easier if the metal formed is in the liquid state at the temperature of reduction
(ii)The reduction of Cr2O3 with aluminium is thermodynamically feasible, yet it does not occur at room temperature (iii) Pine oil is used in froth floatation method
13. (a) Are all the bonds in PCl5 equivalent in length?
(b) Ka1 Ka2 for H2SO4 in water.
(c) How many P-OH bonds are present in Pyrophosphoric acid?
14. Complete the following equations:
(a) P4 + SOCl2
(b) NH3 + CuSO4(aq)
(c) PbS + O3
15. How would you manufacture H2SO4 by contact process?
16. Complete the following equations:
(a) HgCl2 + PH3
(b) P4 + NaOH + H2O
(c) Cl2 + NaOH(hot&conc.)
17. Complete the following equations:
(i) P4 + SOCl2
(ii) NH3 + CuSO4(aq)
(iii) XeF6 + H2O
18. Describe the preparation of potassium permanganate by Pyrolusite.
19. How does the acidified permanganate solution react with (i) SO2 and (ii) oxalic acid?
20. Describe the oxidizing action of potassium dichromate with (i) Iodide and (ii) H2S
Numericals (2/3marks questions)
1. The edge length of a unit cell having molecular weight 75g/mol is 5 A0 which crystallizes in bcc lattice. If the density is 2g/cc then find the radius of the metal atom.
2. Analysis shows that nickel oxide has formula Ni 0.98 O 1.00 .What fraction of nickel exist as Ni 2+ and Ni 3+.
3. An element has bcc structure with cell edge of 288pm .The density of the element is 7.2 gm /cm3. How many atoms are present in 208 gm of the element?
4. A 5% solution of sucrose C12H22O11 is isotonic with 3% solution of an unknown organic substance. Calculate the molecular mass of unknown substance.
5. Calculate the boiling point of solution prepared by dissolving 3.42g of sugarcane in 100 gram of water. Given for water Kb= 0.52 K Kg mol-1and boiling point of pure water is 373.15 K.
6. A solution is prepared by dissolving 30g of non-volatile non-electrolyte solute in 90g water. The vapour pressure of solution was 2.8 K Pa at 298K. When 18g of water was further added to it, the vapour pressure became 2.9 k Pa at 298K. Calculate molar mass of solute.
7. 2gm of benzoic acid in 25gm of benzene show a depression in freezing point equal to 1.62K.Molal depression constant for benzene is 4.9KKg/mol. What is the percentage association of benzoic acid if it forms a dimer in solution?
8. Λ0m for NaCl ,HCl and NaAc are 126.4,425.9 and 91.0 SCm2/mol respectively .Calculate Λ0m for acetic acid.
9. Calculate the potential of hydrogen electrode in contact with a solution whose PH is 10.
10. Write the Nernst equation and find emf of the following cells at 298 K:
Mg(s) Mg2+ (0001 M) Cu2+ (00001 M) Cu(s)
11. . A solution of CuSO4 is electrolysed for 10 minutes with a current of 15 amperes. What is the mass of copper deposited at the cathode?
12. From the following data for a chemical reaction between A and B at 300 K
[A] mol/L [B] mol/L Initial rate (mol L–1 sec–1)
2.5 × 10–4 3 × 10–5 5 × 10–4
2.5 × 10–4 6 × 10–5 4 × 10–3
1 × 10–3 6 × 10–5 1.6 × 10–2
Calculate (i) the order of reaction with respect to A and with respect to B.(ii) the rate constant 300K
13. The decomposition of hydrocarbon follows the equation k = (4.5 × 1011 s–1)e–28000 K/T. Calculate Ea.
14. Show that for a first order reaction, time required for 99% completion is twice for the time required for the completion of 90% of reaction.
15. The decomposition of phosphine
4PH3(g)P4(g) + 6H2(g) has rate law; Rate = k [PH3].
The rate constant is 6.0 × 10–4 s–1 at 300K and activation energy is 3.05 × 105 J mol–1. Calculate the value of the rate constant at 310K. (R = 8.314 J k–1mol–1).
CLASS XII – B,C,D. MATHEMATICS
LEVEL -1
1. If A = {1,2,3,4,5}, write the relation R such that a + b = 8, a, b ϵ A. Write its domain and codomain.
2. Show that the reln R in the set {1,2,3} given by {(1,2), (2,1)} is symmetric but neither reflexive nor transitive.
3. Prove that the Greatest Integer function f(x) = [x], is neither one-one nor onto.
4. Let * be a b.o. on N given by a*b = HCF of a and b, where a, b ϵ N. Write the value of 22*4.
5. If A is a nonsingular matrix of order 3 and |A| = 3, find |3A|.
6. Differentiate y w.r.t. x where y = .
7. Find the area of the parallgm whose adjacent sides are vectors .
8. Show that .
9. Write the equation of a line parallel to the line and passing through (1, 2, 3).
10. Find the distance of the plane 2x - y + 2z + 1 = 0 from the origin.
LEVEL - 2
1. Show that the relation R in the set N given by R = {(a,b) : a is divisible by b and a, b ϵ N} is reflexive and transitive but not symmetric.
2. Show that is both one-one and onto.
3. Examine whether the following is a b.o:
a*b = (a + b)/2, a,bϵ Q . And if so, then check if * is commutative and associative.
4. If A is a nonsingular matrix of order 3 and |A| = 7, find |adj A|.
5. If y = sin-1 x, show that
6. Find the area of aparallgm whose diagonals are the vectors .
7. Show that the vectors are coplanar.
8 . Show that the lines and intersect; also find their point of intersection.
9. Find the image of the point (1, -2, 1) in the line .
10. Find the distance of the point (3,4,5) from the plane x + y + z = 2 measured // to the line
2x = y = z.
LEVEL - 3
1. Show that the reln R on A = { x: x ϵ Z, 0<x<12} given by R = {(a,b): |a – b| is a multiple of 4} is an equivalence relation. Find the equivalence class of 2.
2. Consider a function defined by f(x) = 9x3 + 6x – 5. Show that f is invertible and
, where R = (0, .
3. Let X be a non-empty set and * be a b.o. on P(X), the power set of A, defined by A*B = A U B, for all A, B ϵ P(X). Prove that * is both commutative and associative on P(X). Find the identity element w.r.t. * on P(X). Also show that ϵ P(X) is the only invertible element of P(X).
4. A square matrix A of order 3, has |A| = 5; find |A. adj A|.
5. Find if .
6. If are p. v of the vertices of a triangle ABC. Then show that the area of the triangle is
.
7. Find the value of x if the points A(4, 1, 2), B(5, x, 6), C(5, 1, -1) and D(7,4,0) are coplanar.
IN ADDITION TO THE ABOVE , WORK OUT ANY TWO SAMPLE PAPERS FROM THE GIVEN ONES
IN YOUR KVS STUDY MATERIAL/ANY REFERENCE BOOK/GUIDE, IN A SEPARATE COPY AND SUBMIT IT TO ME AFTER WINTER BREAK.
WINTER BREAK HOLIDAY HOMEWORK 2017-18(MATHEMATICS)
CLASS XII A (MATHEMATICS)
Level 1
1) Complete solution of 5 sample papers
2) Practice from Ch 1 to Ch 13
Level 2
1) Complete solution of 5 sample papers
2) Practice from Ch 1 to Ch 13
3) Solution of minimum questions given ( Selected)
Level 3
1) Practice from Ch 1 to Ch 13
2) Solution of minimum questions given.(Selected)
CLASS XI B,C,D (MATHEMATICS)
Level 1
1) Complete solution of 5 last year papers
2) Practice from Ch 1 to Ch 11
3) Power point presentation
Level 2
1) Complete solution of 5 last year papers
2) Practice from Ch 1 to Ch 11
Level 3
1)Practice from Ch 1 to Ch 11
CLASS VIII B & C (MATHEMATICS)
Level 1
1) Self study of chaper 13
2) Practice from Ch 1 to Ch 12 (Practice Copy)
3) Solution of questions fromCh 1 to Ch 12 (Fair Copy)
Level 2
1) Practice from Ch 1 to Ch 12 (Practice Copy)
2) Solution of questions fromCh 1 to Ch 12 (Fair Copy)
Level 3
1) Practice from Ch 1 to Ch 12 (Practice Copy)
2) Solution of questions fromCh 1 to Ch 12 (Fair Copy)
3) Minimum questions to be solved.
B Bhakta
PGT MATHS
CLASS: XII SUBJECT : BIOLOGY
Common to all:
- Solve last five years AISSCE question papers.
- Complete Practical record in all aspects and submit on reopening of the vidyalaya.
- Complete Investigatory Project record in all aspects and submit on reopening of the vidyalaya.
- Read and studythe Study materials provided.
For L1 students:
a) Collect 5 HOTS and 2 VBQ questions from each lesson (lesson 1 to 16) and solve them.
b)Practice Drawing labeled diagrams given in the textbook lessons.
c)Prepare the list of flow charts and tables given in the lessons, write and learn them.
d) Find 5 terms/ definitions from each lesson, write and learn them.
e) Read the text book beginning to end atleast once and find your grey areas if any.
For L2 students:
a)Practice Drawing labeled diagrams given in the textbook lessons.
b)Prepare the list of flow charts and tables given in the lessons and learn them.
c)Find 5 terms/ definitions from each lesson, write and learn them.
d)Collect 2 HOTS and 1 VBQ questions from each lesson (lesson 1 to 16) and solve them.
e)Prepare the list of difficult topics/ areas chapter wise and consult for individual doubt redressal over phone (9508426865) / on opening of the Vidyalaya.
For L3 students:
a)Practice Drawing labeled diagrams given in the textbook lessons.
b)Prepare the list of flow charts and tables given in the lessons and learn them.
c)Find 5 terms/ definitions from each lesson, write and learn them.
d) 1 VBQ questions from each lesson (lesson 1 to 16) and solve them.
Prepare the list of difficult topics/ areas chapter wise and consult for individual doubt redressal over phone (9508426865) / on opening of the Vidyalaya.
CLASS XII HISTORY
CATEGORY 1
- Prepare a practical file
- Study material( focus and learn the important questions)
- Map work(Imp. Sites)
- Learn important questions discussed in class
- Revise and prepare for pre board exams
CATEGORY 2
- Prepare a practical file
- Study material( focus and learn the important questions)
- Map work(Important and extra sites)
- Learn important questions discussed in class
- Revise and prepare for pre board exams
- Also prepare extra questions discussed in class