# Hol. H.W. Class 12 Sci.

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**THE JAIN INTERNATIONAL SCHOOL, KANPUR**** **

**SUMMER VACATION HOMEWORK (2016-2017)**

** CLASS-XII Science **

** **

**ENGLISH:**** **Read the Novel- ‘The Invisible Man’

**SCIENCE**

**PHYSICS:** Solve NCERT Questions of the chapters covered in your registers.

Do the assigned project.

**CHEMISTRY**: Solve the given worksheet in Notebook.

**BIOLOGY**: Complete your project assigned.

** **Write all the experiments in your lab manual. (Leave space for Observation).

**MATH****:** : Solve the given work sheet in notebook**.**

**OPTIONAL SUBJECTS**

**PHYSICAL EDUCATION:** complete the given project work.

**COMPUTER SCIENCE**: File to be completed and ‘Work Done Throughout the Year’.

**INFORMATION PRACTICES:** File to be completed and ‘Work Done Throughout the year’.

**FASHION STUDIES:** Complete project on ‘Fashion Capitals’.

_______________________HAPPY HOLIDAYS__________________________

**THE JAIN INTERNATIONAL SCHOOL, KANPUR**

**CLASS- XII (2016-17)**

**SUB: CHEMISTRY WORKSHEET SUMMER HOLIDAY HOME-WORK **

Q1)

a)A cubic solid is made up of two elements X and Y. Atoms Y are present at the corners of the cube and atoms X at the body center. What is the formula of the compound? What are the co- ordination numbers of X and Y?Ans XY, 8

b)A compound is formed by the two elements M & N. the element N forms ccp and atoms of M occupy 1/3rd of tetrahedral voids. What is the formula of compound? Ans- M_{2}N_{3}

c)Ferric oxide crystallizes in the hcp array of oxide ions with two of the every octahedral void occupied by the ferric ions. Derive the formula of ferric oxide. Ans Fe_{2}O_{3}

Q2) Niobium crystallizes in body-centered cubic structure. If density is 8.55 g cm^{–3}, calculate atomic radius of niobium using its atomic mass 93 u. Ans- 14.29 nm

Q3) If the radius of the octahedral void is r and radius of the atoms in close packing is R, derive relation between r and R.

Q4) Silver forms ccp lattice and X-ray studies of its crystals show that the edge length of its unit cell is 408.6 pm. Calculate the density of silver (Atomic mass = 107.9 u). Ans- 10.5 g cm^{-3}

Q5) KF has NaCl structure. What is the distance between K^{+} and F^{-} in KF, if its density is 2.48 g/cm^{3}.

Ans- 268.7 pm

Q6) CsCl has cubic structure. If Its density is 3.99 g/cm^{3}.What is the distance between Cs^{+}&Cl^{¬}ions (atomic mass of Cs is 133) Ans- 357 pm

Q7) Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is 1.504 g mL^{-1 }Ans- 16.23 M

Q8) How many ml of 0.1 M HCL are required to react completely with 1 g mixture of Na_{2}CO_{3} and NaHCO_{3} containing equimolar amount of both? Ans- 157.8 mL

Q9) 200 cm3 of an aqueous solution of a protein contains 1.26 g of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 × 10^{-3} bar. Calculate the molar mass of the protein. Ans- 61,038

Q10) If N_{2} gas is bubbled through water at 293K, how many milimoles of N_{2} gas would dissolve in 1 liter of water. Assume that N_{2} exerts a partial pressure of 0.987 bars. Given that Henry’s constant for N_{2} at 293K is 76.48 kbar. Ans- 0.716

Q11) Two elements A and B form compounds having formula AB_{2} and AB_{4}. Whendissolved in 20 g of benzene (C_{6}H_{6}), 1 g of AB_{2} lowers the freezing point by2.3 *K *whereas 1.0 g of AB_{4} lowers it by 1.3 *K*. The molar depression constantfor benzene is 5.1 *K *kg mol^{–1}. Calculate atomic masses of A and B. Ans- A = 25.58 u and B = 42.64 u

Q12) A solution is prepared by dissolving 2 g of sucrose and 2g of urea in 100 g water at 298K. Calculate the VP of the solution, if the VP of pure water is 23.756 torr. Ans- 23.590 torr

Q13)

a) A 5% solution (by mass) of cane sugar in water has freezing point of 271K.Calculate the freezing point of 5% glucose in water if freezing point of purewater is 273.15 K. Ans- 269.07K

b) 18 g of glucose, C_{6}H_{12}O_{6}, is dissolved in 1 kg of water in a saucepan.At what temperature will water boil at 1.013 bar? K_{b} for water is 0.52K kg mol^{-1}. Ans- 373.202 K

(water boils at 373.15 K at 1.013 bar pressure)

Q14)

a) 19.5 g of CH_{2}FCOOH is dissolved in 500 g of water. The depression in the freezingpoint of water observed is 1.00 C. Calculate the van’t Hoff factor and dissociationconstant of fluoroacetic acid.

b) Determine the amount of CaCl_{2} (i = 2.47) dissolved in 2.5 litre of water such that its osmotic pressure is 0.75 atm at 27° C. Ans- 0.03 mol

Q15) Phenol associate in benzene to a certain extent for a dimer. 2g of phenol when dissolved in 100g of benzene lowers the freezing point by 0.69^{o}C. Calculate degree of association of phenol.

(K_{f}= 5.12 K mol^{- }kg)

_______________________HAPPY HOLIDAYS__________________________

**THE JAIN INTERNATIONAL SCHOOL, KANPUR**

**CLASS- XII (2016-17)**

**SUB: Mathematics WORKSHEET SUMMER HOLIDAY**** HOME-WORK **** **

** 1. Find the values of ‘a’ and ‘b so that function is a continuous function **

** **** **

** 2. Determine f(0) so that the function f(x) defined by F(x) = **** **** 3. Let f(x) = **** c**** **

** If f(x) is continuous at x=**** , find a&b**

**4. The points of discontinuity of the function**

** ** F(x) =** **

**5. Discuss the differentiability of f(x) = x|x| at x=0**

**6. For what values of a&b is the function**

** F(x) = **** is differentiable at x=c**** **

**7. ****Differentiate **** w.r.t.(sinx) ^{x}**

**8. Find ** , ** x ^{y}=y^{x} **

** 10. If y=2x tan ^{-1}x –log (1+x^{2}), prove that **

**= 2 tan**

^{-1}x

**9. If x ^{y} =e^{x-y}, then prove that **

**= 2 tan**

^{-1 }x

** 10. If y= Asinx +B cosx then show that **** **

**11. If x =sin and y=sinpt, then show that **** +**** **

** **

** y= (tan ^{-1}x)^{2} , show that (1+x^{2})^{2}y_{2} + 2x (1+x**

** If y= **** ,show that (1-x ^{2})**

**-3x**

**- y = 0**

** If y =****, find **** **** 14. If ****= xy , show **** **

** **_______________________HAPPY HOLIDAYS__________________________