Kendriya Vidyalaya No. 1 Satna

CLASS – XII CHEMISTRY WORKSHEET FOR SUMMER VACATION HOME WORK:

WORKSHEET : 1 (SOLID STATE )

1. How do the structures of quartz and quartz glass differ?

2. Why is the window glass of the old buildings thick at the bottom?

3. Why is frenkel defect not found in pure alkali metals?

4. What type of stoichometric defect is shown by : (i) ZnS (ii) AgBr

5. A group 14 element is to be converted into n- type semiconductor by doping it with a suitable impurity. To

which group should this impurity belong?

6. a) What is meant by the term coordination number? b)what is the coordination number of atoms i) In cubic

closed packed structure? ii) In a body centered cubic structure?

7. Silver crystallizes in fcc lattice. If edge length of the cell is 4.077 x 10-8 cm and density is 10.5gcm-3, calculate

the atomic mass of silver. (Ans. 107.12g mol-1)

8. A cubic solid is made of two element P and Q. atoms of Q are at the corners of the cube and P at the body-

center. What is the formula of the compound? What are the coordination numbers of P and Q?

9. Niobium crystallizes in body centered cubic structure. If density is 8.55g cm-3 , calculate atomic radius of

niobium using its atomic mass 93u. (Ans. 14.29x10-7cm)

10. Copper crystallizes into a fcc lattice with edge length 3.61x10-8cm. Show that the calculated density is in

agreement with its measured value of 8.92g cm-3 . (Ans. d = 8.96g cm-3)

11. An element (at. Mass = 60) having face centred cubic unit cell has a density of 6.23 g cm-3. What is the edge

length of the unit cell? (Ans. 400 pm)

12. A body centred cubic element of density 10.3g cm-3 has a cell edge of 314 pm. calculate the atomic mass of

the element (Ans. 96g mol-1)

13. An element A crystallizes in fcc structure. 200g of this element has 4.12x1024 atoms. The density of A is 7.2g

cm-3. Calculate the edge length of the unit cell. (Ans. 6.46x10-8cm)

14. Sodium crystallizes in the cubic lattice and the edge of the unit cell is 430pm. calculate the number of atoms

in a unit cell. (At mas of Na=23 amu, density of sodium=0.9623g cm-3, NA=6.023x1023 mol-1) (Ans. z = 2)

15. Iron has a body centred cubic unit cell with cell edge of 286.65pm. the density of iron is 7.87 g cm-3. Use

this information to calculate Avogadro’s number. (At mass of Fe = 56g mol-1) (Ans. 6.043x1023 mol-1)

16. A compound froms hexagonal close-packed structure. What is the total number of voids in 0.5 mol of it?

How many of these are tetrahedral voids? (Ans. 9.33x1023)

17. Classify each of the following as being either a p-type or an n-type semiconductor: (a) Ge doped with In (b) B

doped with Si

18. Define the ‘forbidden zone’ of an insulator.

19. What type of substances exhibit antiferromagnetism?

20. Schottky defect lowers the density of the crystal but Frenkel defect does not. Discuss.

21. Explain the following properties giving suitable examples: (a) Ferromagnetism (b) Paramagnetism (c)

Ferrimagnetism.

WORKSHEET 2 ( HALOALKANES AND HALOARENES )

1. Why is sulphuric acid not used during the reaction of alcohols with KI?

2. Arrange each set of compounds in the order of increasing boiling points. a) Bromomethane, Bromoform,

Chloromethane, Dibromomethane. b) 1-Chloropropane, Isopropyl chloride, 1-chlorobutane. 3. Which alkyl

halide from the following pairs would you expect to react more rapidly by an SN 2 mechanism? Explain your

-C-

4. Which of the following has the highest dipole moment? (i) CH2Cl2 (ii) CHCL2 (iii) CCl4

5. What are ambident nucleophiles? Explain with an example.

6. Which compound in each of the following pairs will react faster in SN 2 reaction with OH? (i) CH3Br or CH3I (ii)

(CH3)3 CCl or CH3Cl

7. Explain why (i) the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride? (ii) alkyl

halides, though polar, are immiscible with water? (iii) Grignard reagents should be prepared under anhydrous

conditions?

8. Arrange the compounds of each set in order of reactivity towards SN2 displacement: a) 2-Bromo-2-

methylbutane, 1-Bromopentane, 2-Bromopentane. b) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-

Bromo-3-methylbutane. c) 1-Bromobutane, 1-Bromo-2, 2-dimethylpropane, 1-Bromo-2-methylbutane, 1-

Bromo3-methylbutane.

9. p-Dichlorobenzene has higher melting point and lower solubility than 0- and misomers. Discuss

10. The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohols but in presence of

alcoholic KOH, alkenes are the major products.

11. Which is a better nucleophile, a bromide ion or an iodide ion?

12. What are chiral and achiral objects?

13. What is plane polarized light?

14. What do you understand by the term optical activity of compounds?

15. Explain why thionyl chloride method is preferred for preparing alkyl chlorides from alcohols?

16. What is an asymmetric carbon?

17. Explain as to why haloarenes are much less reactive than haloalkanes towards nucleophilic substitution

reactions. Or Which compound in each of the following pairs will react faster in SN2 reaction with –OH? Why? a)

CH3 Br or CH3I b) (CH3)3CCl or CH3Cl

18. Which ones in the following pairs of substances undergoes SN2 substitution reaction faster and why?

19. Which one in the following pairs undergoes SN1 substitution reaction faster and why?

20. What are enantiomers? Draw the structures of the possible enantiomers of 3- methylpent 1-ene

21. Although chlorine is an electron withdrawing group, yet it is ortho, para-directing in electrophile aromatic

substitution reactions. Why?

22. Answer the following: a) Haloalkanes easily dissolve in organic solvents, why? b) What is known as a racemic

ixture? Give an example. c) Or the two bromoderivatives, C6H5CH(CH3)Br and C6H5CH(C6H5)Br, which one is

more reactive in SN1 substitution reaction and why?

23. Give reasons: a) tert-Butyl chloride reacts with aqueous sodium hydroxide by SN1 mechanism while nbutyl

chloride reacts by SN2 mechanism.

b) Alkyl halides, though polar, are immiscible with water.

c) Vinyl chloride is unreactive in nucleophilic substitution reactions.

d) Neo-pentyl bromide undergoes nucleophilic substitution reaction very slowly.

e) 3-Bromocyclohexene is more reactive than 4-bromocyclohexene in hydrolysis with aqueous NaOH.

f) Iodoform is obtained by reaction of acetone with hypoiodite ion but not iodide ion.

KENDRIYA VIDYALAYA NO.1 SATNA

HOMEWORK - SUB- ENGLISH

CLASS -12TH

SESSION 2018-19 – (MAY to JUNE)

Flamingo:

Chapter: First- ‘The Last Lesson’ : Textbook exercises.

a. Think as you read questions.

b. Understanding the text questions.

c. Writing .

d. Short answer type questions.

e. Long answer type questions.

f. Value based questions.

Chapter: Second. Poem: My Mother at Sixty Six.

A. Summary of the poem

B. Textbook exercises. Think it out.

c. Short answer type questions.

Chapter: Third: Vistas ‘The Tiger King’.

a. Textbook exercises. Read and Find out.

b. Reading with insight.

c. Short answer type questions.

d. Long answer type questions.

e. Value based questions.

Chapter: Fourth: Reading and Writing Skill.

a. Job applications. As suspected in your syllabus.

b. Enquiry Complaint letter. As suspected in your syllabus.

c. Notice and Advertisement,Poster.

KENDRIYA VIDYALAYA No.1 SATNA

SUMMER HOLIDAYS HOMEWORK CLASS XII -2018 MATHEMATICS

01 Do all the solved examples from the text book. 02 Solve the following

1) Let f:N→N be a function defined as f(x) = 4x2 + 12x + 15.Show that f: N→S is invertible(where S is range of f).Find the inverse of f and hence find fS is invertible(where S is range of f).Find the inverse of f and hence find f-1(31) and f-1(87).

2) Consider f:R+→[-5,∞) given by f(x) = 9x2 + 6x – 5, Show that f is invertible with

f-1(y) = √𝑦+6−1

3

3) Show that f:[-1,1] →R given by 𝑓(𝑥) = 𝑥

𝑥+2 is one – one.Find the inverse of the

function f :[-1,1]→Range f. 4) Let A = R – {3} and B = R – {1}.Consider the function f:A→B defined by f(x) =

𝑥−2

𝑥−3.Is f one – one and onto? Justify your answer.

5) Let f:N→N defined by 𝑓(𝑛) = {

𝑛+1

2, 𝑖𝑓 𝑛 𝑖𝑠 𝑜𝑑𝑑

𝑛

2, 𝑖𝑓 𝑛 𝑖𝑠 𝑒𝑣𝑒𝑛

for all nϵN.State whether

the function f is bijective.Justify your answer.

6) Let A = R –{3} and B = R – {2/3}.If f:A →B given by f(x) = 2𝑥−4

3𝑥−9,prove that f

is a bijective function. 7) Show that f:A→A ,A = R – {2/3} defined as f(x) = 4𝑥+3

6𝑥−4 is one- one and

onto.Hence find f-1. 8) Define a binary operation * on the set [0,1,2,3,4,5} as

a*b = {𝑎 + 𝑏, 𝑖𝑓 𝑎 + 𝑏 < 6

𝑎 + 𝑏 − 6 , 𝑖𝑓 𝑎 + 𝑏 ≥ 6

Show that zero is the identity for this operation and each element a≠0 of the set is invertible with 6 – a being the inverse of a.

9) Prove that the relation R in the set A = {5,6,7,8,9} given by R = {(a,,b): |a - b|is divisible by 2}is an equivalence relation. Find all elements related to element 6.

10)Prove that the relation R in the set A = {xϵZ : 0≤ x ≤12} given by R = {(a,,b): |a - b| is a multiple of 4}is an equivalence relation.

11)let A = NxN and * be a binary operation on A defined by (a.b)*(c,d) = (a + c, b + d).Show that * is commutative and associative. Also find the identity element for * on A, if any.

Kendriya Vidyalaya No.1 , Satna

Topic Electrostatic

Class-XII

Subject-Physics

_________________________________________________________________________

1. ceahC iG C n,C ai ,C ciw,C iaahC,C caSiCaiS,yC Wa.C hcC cC iGC hGci ialSC mah ,C ahC iG C n,C iS,C

c,whClG iCalSy 2

2. Two charges of magnitude +4Q and –Q are located at points (a,0) and (-3a,0) respectively. What is

the electric flux due to these charges through a sphere of radius 2a with its Centre at the origin?

2

3. What is the amount of work done in moving a point charge around a circular arc of radius r at the

center of which another point charge is located? 2

4. A charge ‘q’ is moved from a point A above a dipole of dipole moment ‘p’ to a point B below the

dipole in an equilateral plane. Find the work done in this process. 2 5. GC lehGaCmhaaC iC C,aihGC C yC 3-wC 80C c,whClG iCalSC aicC ,nii C , ,CaSlGC iG C al ,C ,Gcha.C iC eC A

,Gaht.Caa,Ca.e,CltCc,whCl iCalSCita,SCCyC3-wC21ChweiSha.C, ,CaSlGCClGC,GaSiahlGChGC,Sic,cCalCiCeC A

lehGay 2

6. Two point charges 4 µC and 1 µC are separated by a distance of 2 m in air. Find the point on the line

joining charges at which the net electric field of the system is zero. 3

7. A charge Q is distributed uniformly over a sphere of radius R. Obtain the expression for electric

field and potential at a point 0 < X < R.

Show a plot the variation of E and V with X for 0 < X < 2R. 3

8. A point charge causes an electric flux -4π x 103 Nm2/C to pass through a spherical Gaussian surface

of 10.0 cm radius centered on the charge. (i) Calculate the value of the point charge.

(ii) If the radius of Gaussian surface were doubled, how much flux would pass through the surface ?

3

9. If a dipole of length ‘1a’ is kept in uniform electric field E0 , diagrammatically represent the position

of the dipole in stable and unstable equilibrium and derive the expression for (i) torque (ii)

potential energy. 3

10. Use Gauss’s theorem to find the electric field due to uniformly charged infinitely large plane thin

sheet with surface charge density 3

11. A charge of 24 micro coulomb is given to a hallow sphere of radius 0.2 m, find the potential

(i) at the surface of the sphere,

(ii) at a distance of 0.1 m from the centre of the sphere

(iii) at the centre 3

12. Use Gauss’s theorem to find the electric field due to uniformly charged infinitely large straight wire.

3

13. Calculate the work done to disassociate the system of three charges placed at the vertices of an

equilateral triangle of side ‘a’ as shown below. 3

14. Discuss the condition At a point where

(i) Electric field is zero but potential is not zero

(ii) Potential is zero but Electric field is not zero

15. ABCD is a square of side 5 m. Charges 50 C, -50 C and 50 C are placed at A,C and D respectively. Find

the magnitude of net electric field at B. 3

KendriyaVidyalayaSatna No.1 Summer holidays homework 2018-19

Class-12th Subject – Biology

Q:- Prepare full topic for Summer Holiday (Home Work) Name Wise topic as follows

Student Name Topic name

Laxmi Reproduction in animal

Nikita Sexual reproduction in flowering plant

Avantika Human reproduction

Sonam dwivedi Reproductive health

Aditi gupta Principal of inheritance and variation

Neha tiwari Molecular basis of inheritance

Kanchan Evolution

Ravi kushawaha Human health and disease

Anuj ku pandey Strategies for enhancement for food production

Shalini prajapati Transcription process

Pawan singh Translation process

Shivani singh Organism and population

Md yasir khan Transgenic animal and plants

Ruchi tiwari Recombinant dna technology

Simranjeet Ecosystem

Amit singh Biodiversity and conservation

Anjali singh Environmental issues

Swati soni Nitrogen cycle

Aryan singh DNA replication

Vishal aditya DNA finger printing

कें द्रीय विद्यालय क्रमाांक 01, सतना कक्षा - बारहि ीँ विषय: हहन्दी

ग्र ष्मािकाश गहृ कायय प्रश्न 1 पल्लिन एि ँसँक्षपेण के मूलभाि को समझते हुए दोनो की पररभाषा ललखिए तथा दोनो के दो-दो उदाहरण भ ललखिए ।

प्रश्न 2 ननम्नललखित विषयोँ पर ननबांध ललिकर लाइए –

1 ज िन-दानयत्ि बोध

2 लशक्षा का महत्ि

3 मैँ और मेरा भविष्य

प्रश्न 3 आलोक धांिा के ज िन-पररचय को ललिते हुए “पतँग “ कविता का भािाथय ललखिए ।

प्रश्न 4 “सबसे तेज बौछारेँ गय ीँ ,भादो गया” के बाद प्रकृनत मेँ जो पररितयन कवि ने हदिाया है ,उसका िणयन अपने शब्दोँ मेँ करेँ ।

प्रश्न 5 पतँगोँ के साथ िे भ उड रहे हैं – बच्चोँ का उडान से कैसा सम्बांध बनता है ?

प्रश्न 6 महादेि िमाय के ज िन पररचय को ललिते हुए “भक्ततन “ नामक सँस्मरणात्मक रेिाचचत्र का साराँश ललखिए ।

प्रश्न 7 भक्ततन अपना िास्तविक नाम लोगोँ से तयोँ छुपात थ ? भक्ततन को यह नाम ककसने और तयोँ हदया होगा ?