SAFFRON PUBLIC SCHOOLAshoka Enclave-II, Sec-37, Faridabad

Class-XII Sc.

Summer Holiday Homework -2020-21

CHEMISTRY SECTION-A1. A decimolar solution of potassium ferrocyanide is 50% dissociated at 300K.Calculate the value of Van’t Hoff factor for potassium ferrocyanide.2.A solution prepared by dissolving 1.25g of oil of winter green in 99g of benzene has a boiling point of 80.310C.Determine the molar mass of this compound (Boiling point of pure benzene =2.530Ckg/mol)3.What mass of ethylene glycol must be added to 5.50kg of water to lower the freezing point of water from00C to -10.00C?(Kf for water =1.86Kkg/mol)4. 15g of an unknown molecular substance was dissolved in 450g of water. The resulting solution freezes at -0.340C.What is the molar mass of the substance?( Kf for water =1.86Kkg/mol)5. Henry law constant for CO2 dissolved in water is 1.67x108Pa at 298K.Calculate the quantity of CO2 in 1L of soda water when packed under 2.5atm CO2 pressure at 298K.6. The boiling point of elevation of 0.30g acetic acid in 100g benzene is 0.0633K.Calculate the molar mass of acetic acid from this data. What conclusion can you draw about the molecular state of the solute in the solution? Given Kb for C6H6=2.53Kkg/mol.7.How much urea should be dissolved in 50g of water so that its vapour pressure at room temp is reduced by 25%.Calculate molality of the solution obtained.8. What concentration of nitrogen should be present in a glass of water at room temperature? Assume a temperature of 250C,a total pressure of 1 atm and mole fraction of N2 in air of 0.78(KH for N2= 8.42x10-7M/mmHg).9. Draw the structures and explain hybridization of 1)XeOF4 4)HClO3

2)XeF4 5)SF4

3)ClF3 6)H2S2O7

10. Account for the following: 1) Flourine always exhibit an oxidation state of -1 only in its compounds. 2) Dioxygen is a gas while Sulphur is a solid. 3) Noble gases have large positive values of electron gain enthalpy.

4)HF is least volatile whereas HCl is the most volatile.11. a)Describe the principle of extraction of Fe,Zn,Cu and Al from their ores along with suitable diagram. b)Outline the principles of refining of metals by the following methods 1)electrolytic refining 2)Zone refining 3)Vapour phase refining12.a) Write similarities between lanthanide and actinide b)Prepare KMnO4 and K2Cr2O7 from their respective ores

13. A) State Hardy-Schulze ruleB) Differentiate between 1) Chemisorpton & Physisorption

2) Lyophilic & Lyobhobic3) Multmolicular & associated colloids4) Catalyst & Enzyme

SECTION-B14.Learn salt analysis and write related experiment in Practical file.15. Search the theoretical material for the allotted investigatory project, make a rough file and plan the course of action.

PHYSICSUnit I: Electrostatics

Chapter–1:

Electric Charges and Fields Electric Charges; Conservation of charge, Coulomb's law-force between two point charges, forces between multiple charges; superposition principle and continuous charge distribution. Electric field, electric field due to a point charge, electric field lines, electric dipole, electric field due to a dipole, torque on a dipole in uniform electric fleld. Electric flux, statement of Gauss's theorem and its applications to find field due to infinitely long straight wire, uniformly charged infinite plane sheet and uniformly charged thin spherical shell (field inside and outside).

Chapter–2:

Electrostatic Potential and Capacitance Electric potential, potential difference, electric potential due to a point charge, a dipole and system of charges; equipotential surfaces, electrical potential energy of a system of two point charges and of electric dipole in an

electrostatic field. Conductors and insulators, free charges and bound charges inside a conductor. Dielectrics and electric polarisation, capacitors and capacitance, combination of capacitors in series and in parallel, capacitance of a parallel plate capacitor with and without dielectric medium between the plates, energy stored in a capacitor.

Unit II: Current Electricity

Chapter–3: Current Electricity Electric current, flow of electric charges in a metallic conductor, drift velocity, mobility and their relation with electric current; Ohm's law, electrical resistance, V-I characteristics (linear and non-linear), electrical energy and power, electrical resistivity and conductivity, Carbon resistors, colour code for carbon resistors; series and parallel combinations of resistors; temperature dependence of resistance. Internal resistance of a cell, potential difference and emf of a cell, combination of cells in series and in parallel, Kirchhoff's laws and simple applications, Wheatstone bridge, metre bridge. Potentiometer - principle and its applications to measure potential difference and for comparing EMF of two cells; measurement of internal resistance of a cell.

All MCQ and fill up of reference book be learned.

All n.c.e.r.t numerical and exercise questions to be solve in fair notebook.

Assignment will be send on whatsapp group.

BIOLOGY

Q4. Prepare one investigatory project. (as discussed)

ENGLISH1. Make a news letter and write and paste all the writing skills on it Advertisements, Posters, letter to editor, Report and Article.(project work)2. Draft Advertisements for the following (2 each): A. Household item for sale B. To-let C. Required/Vacancy D. Matrimony

E. Services (Showroom/Gym/Coaching etc.)3. Write articles on the following topics: a) Women Empowerment/How safe are women? b) Deteriorating Values amongst the youth. c) Importance of Time Management.4. Read English Newspaper daily. 5. Listen to the English News daily.6. DO 5 comprehension and 5 note making any practice / resource book. MATHS

COMPUTER SC.Make 20 programs using functions.

WEB APPLICATION1. Create a website on " Causes and effects of Covid'19 " using HTML tags such as ( Paragraph, Table , link, image, audio, video)2. Create a movie on " Worldwide lockdown bringing families closer "  using  Window Movie maker

PHYSICAL EDUCATIONMaintain fair copy of first 3 chapters for both 11th and 12th and make practical manual of physical education.

RETAIL1. Prepare a project based on CBSE guidelinesSuggested topics are-

Display of products Non-Store Retailing Point-of –Sale Accounting Procedures in retailing Inventory Handling

Students should prepare the Project as per the following headings:-OAcknowledgementO IndexO Cover pageO Introduction of the concept O Analysis/explanation and interpretationO Conclusion O List of resources used / BibliographyThe project should be handwritten on A4 size coloured designer sheet, an independent & self-directed piece of study.

2. Make an advertisement of any product on A4 size colours sheet.3. Design a Pamphlet for your store to offering discount.4. Design a logo for launching a product manufactured by you.

Revise the entire syllabus covered till May in the e-class.

TOURISM1. Prepare any two project based on CBSE guidelines from the following suggested topics: -*Global Distribution System *Role of NHAI in India.*Prerequirements for Itinerary Preparations.

Students should prepare the Project as per the following headings:-O AcknowledgementO IndexO Cover pageO Introduction of the concept O Analysis/explanation and interpretationO Conclusion O List of resources used / BibliographyThe project should be handwritten on A4 size coloured designer sheet, an independent & self-directed piece of study.

2. Make a Brochure to invite customer for foreign visit on A4 size colours sheet.3. Compare different companies pamphlet to visit Switzerland, Singapore, USA with different benefits.4. Write rules of IATA in India to establishing Travel Agency .5. Effect of Covid-19 on world-wide Tourism Business.

Revise the entire syllabus covered till May in the e-class.PAINTINGSTheory - Read and write on your notebook 

1. Rajathani school of miniature painting                                             2. Pahari school of miniature painting.Practical- Landscape painting -2               Composition -2               Still Life-2