Chemistry homework of XII

1.Define enthalpy of combustion. Heat of formation of ethyl alcohol, water and carbon dioxide are- 64.1Kcal , -68.5Kcal and -95 Kcal respectively.  Calculate the heat of combustion of ethyl alcohol.
2.Distinguish between exothermic and endothermic reaction
3.Distinguish spontaneous and non spontaneous processes giving an example of each.
4.what are the driving forces for spontaneous processes? Justify with examples.
5.Write the general methods of preparation of chloroethane.
6.Describe the laboratory preparation of ethoxy Ethane.
7.What are the criteria for a substance to be primary Standard?
8.What is normality factor ? Distinguish between end point and equivalence point in titration.
9.Define equivalent weight of an element. How is equivalent weight of an acid calculated ?
 To be submitted on given time

Chemistry homework of XI

1.Write two significance of chemical equation.
2.Write four limitations of chemical equation.
3.Define any four types of chemical reactions with examples.
4.Distinguish between valency and oxidation number.
5.Justify the statement that oxidation and reduction go side by side.
6. Check whether the following reactions are redox or not ?
i) H2S + Br2  = 2HBr +S
ii) I2  + HNO3  = HIO3  + NO2 + H2O
iii) AgNO3  + NaCl  =  AgCl  +  NaNO3
7.Describe the synthesis of ammonia by Haber's process. Also write four important chemical reactions of ammonia has.
8.State Boyle's and Charle' s law and derive the relationship, PV = nRT , Where the letter's have their usual meanings.
 To be submitted on given time

PHYSICS (XI) – To be submitted on 12th Bhadra

•          PHYSICS (XI) – To be submitted on 12th Bhadra
1) A simple pendulum has length 1m. The amplitude of the pendulum is 1cm.Find velocity at lowest point and acceleration at highest point.
2) What is second pendulum?
3) A simple pendulum has period 4.2 sec. When it's length is shortened by 1m, the period is 3.7 sec. Find length and value of g.
4) What force is required to stretch a steel wire of cross-sectional area 1square cm to double it’s length?
5) Is a physical quantity having magnitude and direction necessarily a vector quantity? Explain.
6) State and explain the triangle law of vector addition. Find magnitude and direction of resultant.
7) Does coefficient of linear expansion depend upon original length?
8) Describe a method to find coefficient of linear expansion.

PHYSICS (XII) - To be submitted on 13th Bhadra

PHYSICS (XII) - To be submitted on 13th Bhadra
1) State series and parallel combination of resistance. Explain.
2) At what temperature the velocity of sound in air is increased by 50% to that at 27°C.
3) State and explain Ampere's theorem and use it to find magnetic field due to long straight conductor carrying current.
4) In the Bohr's model of hydrogen atom the electron circulates round the nucleus in a path of radius 5.1×10^-11m at frequency of 6.8×10^15Hz. What value of B is set up at the center of the orbit.
7) Why gas becomes conducting at low pressure and high temperature?
8) Why clock oil is used in Millikan's Experiment?

Chemistry homework of XI

1.Calculate the no. of carbon atom and oxygen molecule in 20 g of CaCO3.
2.The cost of table sugar ( C6H12O6) is Rs 85 per kg. Calculate the cost of 1.5 moles of sugar.
3.Calculate the amount of mass in 2.24 litre of CO2 gas at NTP. How many no. of molecules are present in it ?
4.Explain the manufacture of ammonia by Haber' s process.
5.Distinguish between pyrometallurgy and Electrometallurgy
6.State and explain Charle's  law.
7.Define absolute zero and absolute scale of temperature

To be submitted on given time

Chemistry homework of xii

 To be submitted on given time









1) A sample of Na2CO3 weighing 0.53 g is added to 100cc of 0.1 Ñ H2SO4 solution. Will the resulting solution be acidic or basic or neutral ?
2)0.18 g of a metal was completely dissolved in 100 cc of N/2 HCl soln .The volume was then made up to 500 cc . 25 cc of this diluted acid required 17.5 cc of N/10 alkali for complete neutralization. Find the equivalent weight of metal.
3) 1.5 g of an  acid having molecular weight 90 required 33.2 cc  of 1 N NaOH for complete neutralization . Calculate the basicity of an acid.
4) 25 cc of NaOH solution neutralizes exactly 22.5 cc  of a solution ( containing 1.4175 g in 250 cc)  of a dibasic acid of the molecular weight 126, and 10 cc of the same NaOH solution neutralizes exactly 8 cc of H2SO4 solution. Find the strength of H2SO4 solution in terms of normality

5)Define bond dissociation energy.
6)Write two limitations of first law of thermodynamics.
7)Define enthalpy of combustion. Enthalpy of formation of benzene is 55KJ, enthalpy of formation of water and carbondioxide  are -395KJ and -285 KJ respectively. Calculate the enthalpy of combustion of benzene.



To be submitted on given time

Physics XII

Homework to be submitted on of Bhadra
1.      A galvanometer coil has resistance 50Ω and current 30 MA  .How can you current it into 
         i) ammeter (0-5A)
         ii) voltmeter (0-10)
2.       what is galvanometer .How can you convert it into ammeter and voltmeter
3.       Find the total resistance in the following circuit




1. At what temperature would be the speed of sound in oxygen be the same as tha tin nitrogen at 30 O⁰ C ? Given their densities at 0⁰ C are in the ratio 8:7
2. What is the % change in speed pf sound i gas when the absolute temperature is increased by
125% ?
3. Why is sound heard distinctly at night than in the day time ?
4.    What is hall effect ? Obtain an expression for the Hall emf in terms of area of cross dection , width of strip , magnetic field strength &current in strip
5. What do you mean by current sensitivity ? What are the way to increase sensitivity of galvanometer
6. A horizontal wire wire 0.1 m long carries a current of 5A .Find the magnitude and direction of the magnetic field which can support the weight of wire assuming its mass to be 3x10^-4 kg  

XI Physics

Homework to submitted on 5th of Bhadra

1.         What is necessary and required condition for SHM ?             2
2.          For which value of displacement PE and KE of Harmonic bodies are equal ?   2
3.          State and explain energy of SHM           4
4.           Demonstrate the phase two vibrating body in graph
5.           Differentiate between accuracy and precision
6.           Check the correctness of formula F=6ηrv
7.           Taking force ,velocity and mass as basic quantity .Find dimensional formula of time in                         terms of those basic quantity  

Chemistry homework of 11

1. Represent Boyle's law graphically.
2.State and explain Charle' s law.
3.Define absolute zero and represent it by plotting graph.
4.Define acid radical and basic radical with example.
5.What is oxidation number? What are the rules for calculating oxidation number ?
6.Define oxidation and reduction in terms of electronic concept.
7.Write one use of the following: i)Protium ii)Deuterium iii)Tritium iv)Heavy water
8. Show that nascent hydrogen is stronger reducing agent than molecular hydrogen.
9.Distinguish between minerals and ores with examples.
10.Distinguish between alloys and amalgam with examples.
  To be submitted on given time

Chemistry homework 12

1. State and explain first law of thermodynamics. Starting from first law of thermodynamics, derive the relationship, dH= dE + dW , where the letters have their usual meanings.
2. State and explain Hess’s law of constant heat summation. Write it’s one important application.
3. Draw energy profile diagram for both exothermic and endothermic reaction.
4.What is normality ?How is it related with molarity ?
5.Define :I )Binormal solution ii)Seminormal solution iii)Molarity
6. Write short note on law of chemical equivalence
7.What volume of water should be added to 500ml of 2N Na2CO3 to make it exactly N/10 ?
8. 100 ml of 0.1 M NaOH is treated against 0.1 M HCl taken in the brunette. What is the Molarity of the resulting solution when the alkali is half neutralized. Also find the concentration of the salt in mole/litre.
9.Write about the separation of 1 degree, 2 degree and 3 degree amines by Hoffmann’s method.
9.What are amines ?  How are they classified ?
10.Write an example of a) Carbylamine reaction b)Mendius reaction
11.Explain the laboratory preparation of ethoxyethane.
        12.How can you prepare ethoxyethane from a)Ethanol b) Chloroethane
        13.How is ethanamine prepared from a)Propanamide n) Nitroethane
        14.Why alkyl amine is more basic than ammonia ?
        15. An antaacid  tablet containing CaCO3 as an active ingredient requires 22.6 ml of 0.0932 M HCl for complete neutralization .What mass of CaCO3  did the tablet contain ?

 To be submitted on given time

Ù

Physics XII H.W for 2074-4-31

Physics XII

1.     Filament of lamp nearly burnt out at first. After this it continuously glow and gives light. Why?

2.     What is galvanometer? How it is converted into an ammeter and a voltmeter?

3.     Why clock oil is used in Millikan’s oil drop experiment?

4.     What is role of X-Ray in Millikan’s oil drop experiment?

5.     On What factors velocity of sound in air depends? Explain.

6.     Derive an expression for torque experienced by current carrying rectangular coil when kept in magnetic field.

Physics XI H.W for 2074-4-30

Physics XI 

H.W for 2074-4-30

1.     What are the time period and frequency of a body in SHM ?

2.     Name the motion in which velocity is maximum in spite of being zero displacement. Also demonstrate three main character of SHM with the help of figure.

3.     What is phase?

4.     What is linear expansion? Find the length of rod at θ₂ ⁰ C whose length is l₁  at θ₁⁰ C.

5.     Derive relation for energy stored in a stretched wire.

6.     State and explain Hooke’s law. How can you verify it experimentally? 

Chemistry homework 11

1.What are the similarities and differences of hydrogen with alkali metals and halogen ?
2.Give any three reactions to show that nascent hydrogen is stronger reducing agent than molecular hydrogen.
3.Differentiate between: a) Ortho and para hydrogen b)Nascent and molecular hydrogen c)Atomic and molecular hydrogen d)Atomic and nascent hydrogen
4.Define chemical equation. Write it’s applications and limitations.
5. State and explain Boyle’s Law.



To be submitted on 27th, friday

Chemistry XII