Saturday, April 12, 2014

What is denoted by ln?

Question: What is denoted by ln?

Answer: ln is the symbol of natural log. Log is modern symbol.

ln = 2.303 log

Sample paper

General Instructions
1. All questions are compulsory.
2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each.
3. Question nos. 9 to 18 are short answer questions and carry 2 marks each.
4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each
5. Question nos. 28 to 30 are long answer questions and carry 5 marks each
6. Use log tables if necessary, use of calculators is not allowed.

1. Find out the number of atoms per unit cell in a fcc structure having only single
    atoms at its lattice points .                                                                                                                                                                    
2. State the condition resulting in reverse osmosis.                                                                                                        
3. Express the rate of the following reaction in terms of disappearance of hydrogen in the reaction  
     N2 +3H2  ---------->  2NH3     .                                                                                                                     
4. Define molar conductivity for the solution of an electrolyte.                                                                                 
5. PbO2  is a stronger oxidizing agent than SnO2 .                                                                                                                                                                    
6. Why the transition metals generally form colored compounds ?                                                                        
7. Which out of the following are transition element and why?  Zn, Ag, Cd, Au                                                
8. Why is the separation of lanthanide elements  difficult ?                                                                                       
9. Assign reasons for the following    
(i) Phosphorus doped silicon is a semiconductor .
(ii) Schottky defect lowers the density of a solid .                                                                          
10. An element has a body centered cubic  structure with a cell edge of 288 pm.The density
 Of the element is 7.2 g/cm3.Calculate the no. of unit cells in 208 g of the element.                                         
11. Explain the following:
        1.F –centre    2.A hole                                                                                                                                                                                     
12. A 0.1539 molal aqueous solution of cane sugar (mol. Mass = 342 g/mol) has a freezing point                 
 of 271 K While the freezing point of pure water is 273.15 K. What will be the freezing point of
 an aqueous solution Containing 5 g of glucose (mol. Mass =180 g/mole) per 100 g of solution?                 
13. Calculate the standard cell potential of the galvanic cell in which the following reaction takes place
  2 Cr +3 Cd +2  ---------->2 Cr +3   +3 Cd
 Given E0Cr +3 /Cr =0.74 V   , E0Cd +2 /Cd = -0.40 V and F =96500C/mol                                                    
14. Explain the following terms with a suitable example in each case:                                                 
(i) Shape- selective catalysis
(ii)Dialysis                                                                                                                                       
15. (i) What is the role of graphite rod in the electrometallurgy?
(ii) Write the principle of zone refining method.                                                                                                            
16. What is dis -proportionation reaction? Write a chemical reaction to show disproportionation.             
17. What is meant by actenoid contraction? Discuss the important physical properties  of  
        actenoids.                                                                                                        
18. Using valence bond theory predict the shape and magnetic behavior  of [Cr(NH3)6]3+ion.                          
 19. Consider a plot between k vs  where T is the temperature. 
 On the basis of  this plot, answer the following questions 
                 (i)        What is the slope in this line ?
                (ii)         What is the intercept of this line on the y-axis ?
               (iii)         Which area of kinetics is shown by the plot?                                                                            
20. A certain reaction is 50% complete in 20 minutes at 300K and the same reaction is again 50%
     complete in 5 minutes at 350K.Calculate the activation energy if it is a first order reaction.
     Given R=8.314 J/K/mol                                                                                                                                           
21. Describe briefly :
    1. Hardy-Schulze rule
   2.  Peptization
   3.  Electrophoresis                                                                                                                                                     
22. Why is zinc not extracted from zinc oxide through reduction using CO? Give the name of any ore of zinc.                                                                                                                                                                                           
23. Assign a reason for each of the following statements;
1. Phosphinic acid behave as a mono protic acid .
2. More metal fluorides are ionic in nature than metal chlorides
3. Iodine forms I3- ion but F2 does not form F3-ion.                                                                                                 
24. Complete and balance the following equations :
     1. C2H4 +O2 ---------->
      2. 4Al +3O2 ----------->
      3. P4 +SO2Cl2----------->                                                                                                                                                                                 
25. Draw the structures of the following compounds :
     (i) SF4
    (ii) XeF2
   (iii) N2O5                                                                                                                                                                                                                                                                                     
26. Why (I ) Transition metal and their many compounds act as good catalyst.
  (ii) Actinoid contraction is greater from element to element than lanthanoid contraction.
 (iii) K2PtCl6 is a well known compound whereas corresponding Ni compound is not known.                    
27. Write the IUPAC name of [Co(NH3)5(NO2)]( NO3)2  and illustrate  the isomerism  exhibited by this
      Complex compound . Is the name of its isomer differ from this compound?.  
                                                                    OR
 a. Using Valence bond theory, predict the shape and magnetic character of [Ni(CO)4].[Ni=28]
      b. Give one example of application of coordination compounds in medicine.                                          
28. 1.Write the Nernst Equation and calculate the e.m.f  of the following cell at 298 K:
    Cu(s) / Cu2+(0.130M) II Ag+(1.00x10-4M) /Ag(s)
    Given E0   Cu2+ /Cu =+0.34 V and E0   Ag+ /Ag =+0.80 V.                                                                  
      2. Describe the preparation and electrode reactions of fuell cell .                                                               
                                                                    Or
      1. Explain Kohlrausch’s law of independent migration of ions. Write its one application.
      2. How conductivity of an unknown solution be determined? Explain 
29. Discuss the general characterstics of group 15 elements with reference to their :
   1. Electronic configuration   2.Oxidation states   3.Atomic size    
   4. Ionization enthalpy             5.Electronegativity                                                                                               
                                                                            Or
a. Complete and balance the following chemical equations:
 1. F2+H2O(cold)------------->
 2. BrO3- +F2+OH--------------->
  3. Ca3P2+ H2O------------->
b. Write the reaction for thermal decomposition of sodium azide.
c. Why does PCl3 fume in moisture?
30. a. Explain deviation from Raoult’s law in terms of molecular interactions.
b. Vapour pressure of pure water at 298 K is 23.8 mmHg.50 g of urea (NH2CO NH2) is dissolved in
      750 g of water .Calculate the vapour pressure of water for this solution and its relative lowering.      
                                                                               Or
a. Define the following terms :
       1. Mole fraction
       2. Van’t Hoff factor
      b. Calculate the freezing point of a solution containing 18 g of C6H12O6 and 68.4 g of C12H22O11

in 200 g water. The freezing point of pure water is00C and cryoscopic Constant of water is 1.86 K/m.            

Can PCl3 act as an oxidising as well as reducing agent? If yes, how? Illustrate with the help of equations.

Question: Can PCl3 act as an oxidising as well as reducing agent? If yes, how? Illustrate with the help of equations.
ANswer: Yes, PCl3 can act both as an oxidising agent as well as reducing agent.
It react with sulphur tri oxide to reduce it to sulphur di oxide.
PCl3 +SO3  -------------> POCl3 + SO2
It also react with metals like silver and sodium to form their chlorides.

PCl3 + 6 Na ---------------> 3 NaCl +Na3P

What inspired N.Bartlett for forming xenon compounds?

Question: What inspired N.Bartlett for forming xenon compounds?


 Answer: N.Bartlett observed that ionisation enthalpy of xenon is closer to oxygen and got inspired to form similar compound as he made with oxygen by PtF6 as O2PtF6.

What is the relation between butane and 2-methyl propane?

Question: What is the relation  between butane and 2-methyl propane?


Answer:Both are isomers.

What is Henery'sLaw?

Question: What is Henery'sLaw?

Answer: According to this law solubility of a gas is directly proportional to the partial pressure of the gas.Solubility of a gas is represented by its mole fraction in the solution.
Mathematically  P = Kh  X 
where P = partial pressure of gas
Kh = Henery's constant
X = mole fraction of gas
As it is clear from above relationship
X is inversly proportional to Kh
And Kh is found to be decreased by increasing temperature so solubility decreases by increasing temperature.That is why aquatic life is more comfortable in cold water than in hot water.

Show that all the bonds in PCl5 molecule are not equivalent.

Question: Show that all the bonds in PCl5 molecule are not equivalent.
Answer: Since Phosphorus penta chloride  breaks down into phosphorus trichloride and chlorine gas on heating which shows that out of five P-Cl bonds three are equitorial and tightly  bonded and two are axial and weak  bonds.

PCl5  ------------> PCl3 +Cl2 

A compound lens is made of two lenses in contact having powers +12.5 D and -2.5 D. An object is placed at 15 cm from this compound lens.Find the position and nature of the image formed.

Question: A compound lens is made of two lenses in contact having powers +12.5 D and -2.5 D. An  object is placed at 15 cm from this compound lens.Find the position and nature of the image formed.
Answer: Pcomp = P1 +P2 = + 10 D
Fcomp  = 100/10 cm
1/F =1/v - 1/u
F = +10 cm, u = -15 cm, v = ?                                                             
  V= +30 cm 

Image formed will be real inverted and enlarged.

How does NaCN act as a depressant in preventing ZnS from forming the froth?

Question: How does NaCN act as a depressant in preventing ZnS from forming the froth?


Answer: NaCN act as a depressant in preventing ZnS from forming the froth but not for PbS . When an ore containing PbS and ZnS is subjected to froth floatation process only PbS form froth and can be separated.

Which glands contribute fluid to the semen?

Question: Which glands contribute fluid to the semen?    
   

Answer: Prostate gland.

What is Boyale's Law? Explain with suitable example.

Question: What is Boyale's Law? Explain with suitable example.

Answer: According to Boyle’s Law  at constant
temperature, the pressure of a fixed
amount of gas is inversely propotional to its volume.
 Mathematically, it can
be written as
1/p = k V ( at constant T and n)
where k is the proportionality constant,the
value of  k  depends upon the
amount of the gas, temperature of the gas
and the units of  p and V .
On rearranging equation
pV = k

It means that at constant temperature,

Why +5 oxidation state of Bi is less stable than +3 oxidation state?

Question: Why +5 oxidation state of Bi is less stable than +3 oxidation state?


Answer: +5 oxidation state of Bi is less stable than +3 oxidation state due to inert pair effect.

If a stone is thrown vertically upwards, its velocity continusously decreases. Why?

Question: If a stone is thrown vertically upwards, its velocity continusously decreases. Why?


Answer: If a stone is thrown vertically upwards, its velocity continusously decreases because it is thrown against gravity so gravitational force decreases its velocity by pulling it down.

Atoms of element Y form hcp lattice and those of the element X occupy 2/3rd of tetrahedral voids. What is the formula of the compound formed by the elements X and Y?

Question: Atoms of element Y form hcp lattice and those of the element X occupy
2/3rd of tetrahedral voids. What is the formula of the compound formed by the elements X and Y?

Answer: The number of tetrahedral voids formed is equal to twice the number of atoms of element Y and only 2/3rd of these are occupied by the atoms of element X. Hence the ratio of the number of atoms of X and Y is 2

× (2/3):1 or 4:3 and the formula of the compound is X4Y3.

Chemistry question

Question :Classify following as amorphous or crystalline solids: Polyurethane, naphthalene, benzoic acid, Teflon, potassium nitrate, cellophane, polyvinyl chloride, fibre glass, copper.

Answer: Amorphous solids : Polyurethane, Teflon, cellophane, polyvinyl chloride, fibre glass .
Crystalline solids   :  Naphthalene, benzoic acid, potassium nitrate,copper .

Physics

Physics
LONG ANSWER QUESTIONS OF 5 MARKS EACH
Q.1. Find expression for the force and torque on an electric dipole kept in a uniform electric field .
Q.2. Find an expression for the maximum torque acting on an electric dipole when it is placed in a uniform electric field .
Q.3. An electric dipole is held in a uniform electric field (i) using suitable diagram show that it does not undergo any translatory motion , and (ii) derive an expression for the  torque acting on it and specify its direction .
Q.4.An electric dipole of dipole moment p is placed in a uniform electric field E . Write the expression for the torque τ experienced by the dipole . Identify the pairs of perpendicular vectors in the expression . Show diagrammatically the orientation of the dipole in the field for which the torque is (i) maximum (ii) half of the maximum value (iii) zero .
Q.5. Find an expression for the work done in rotating an electric dipole in a uniform electric field .
Q.6.Find an expression for the electric field strength at a distant point situated (i) on the axis and (ii) along the equatorial line of an electric dipole .
Q.7.Derive an expression for the electric potential due to an electric dipole at any point on its axis . Mention the contrasting features of electric potential of a dipole at a point as compared to that due to a single charge .
Q.8. (i) Using Gauss Theorem show mathematically that for any point out side the shell , the field due to a uniformly charged spherical shell is same as the entire charged shell is concentrated at the centre . (ii) Why do you expect the electric field inside the shell to be zero according to this theorem .
Q.9. State Gauss Theorem in Electrostatics . Apply it to find the electric field strength near an infinite plane sheet of charge .

Q.10. Apply Gauss Theorem to obtain the expression for the  electric field at a point due to an infinitely long , thin , uniformly charge straight wire of linear charge density  λ Cm-1 .
General Instructions
1. All questions are compulsory.
2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each.
3. Question nos. 9 to 18 are short answer questions and carry 2 marks each.
4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each
5. Question nos. 28 to 30 are long answer questions and carry 5 marks each
6. Use log tables if necessary, use of calculators is not allowed.

Q: 1)
Give preparation reaction for Terylene.
Q: 2
Write the IUPAC name of

[Pt(NH3)2Cl(NO2)]
General Instructions
1. All questions are compulsory.
2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each.
3. Question nos. 9 to 18 are short answer questions and carry 2 marks each.
4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each
5. Question nos. 28 to 30 are long answer questions and carry 5 marks each
6. Use log tables if necessary, use of calculators is not allowed.

Q: 1) Give preparation reaction for Terylene.
Q: 2 Write the IUPAC name of

[Pt(NH3)2Cl(NO2)]
Q: 3) Write  an example of analgesic  and antipyretic drug.
Q: 4) Out of maltose and sucrose, which is reducing sugar?
Q: 5) What are ambident  nucleophiles?
Q: 6) What happen when benzaldehyde react with aniline in acidic medium?
Q: 7) Give an example of Hoffman bromamide reaction?
Q: 8) What is chemical Adsorption?

Q: 9) 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 of silver =107.9 u ).
Q: 10) Explain the following:

      1)  F –centre

      2) A Hole
Q: 11) Explain the chemistry of lead storage battery  while charging.
Q: 12) How is disproportionation  takes place in chemical  reactions?
Write a chemical reaction to show disproportionation.
Q: 13) Explain the formation of Bakelite.
Q: 14) Give the reasons for:
    1) Haloalkanes though polar ,are insoluble in water.
    2) Grignard reagents should be prepared under anhydrous conditions.
Q: 15) Describe the functions of antibiotics or  antimicrobials. Give an example.
Q: 16) Using valency bond theory predict the shape and magnetic behavior  of

[Co(NH3)6]3+ion.
Q: 17) How will you distinguish between the following chemicals:
     1. Chloroethaneane  and  Bromoethane         
     2. Chlorobenzene and  Chlorocyclohexane
Q: 18) State Henry‘s law and mention its two important applications .                                                                                           
                                                           OR
Calculate the freezing point of a solution containing 18 g of C6H12O6 ,and 68.4 g of C12H22O11 ,in 200 g water.
The freezing point of pure water is 00C and Cryoscopic Constant of water is 1.86 K/m. 
Q: 19) Complete the following :
   1. CH3CH2 CH2NH2 +HCl  ---------------------------------->   
   2. C6H5N2Cl  +H3PO2+H2O -------------------------------->
   3. C6H5N2Cl  +   C2H5 OH----------------------------------->
Q: 20)      1) Write the IUPAC name of  OHCH2CH =CHCH2OH  

      2) Explain the mechanism of hydration of ethene .
Q: 21)       1) What is nucleoside ?
       2) What are water  soluble vitamins?
       3) Give deficiency diseases of vitamin C and D.       
Q: 22) Complete and balance the following equations :
       1. F2+H2O(cold) ---------------------------------->
       2. BrO3- +F2+OH---------------------------------->
       3. Ca3P2+ H2O------------------------------------>
                                                                                          OR
       1. PCl5 +H2O------------------------------------->
       2. KMNO4 +HCl---------------------------------->
       3. S +HNO3--------------------------------------->
Q: 23) Explain
       1) Freundlich adsorption isotherm.
       2) Shape selective catalysts?Give an example of such catalyst.
Q: 24) Calculate the emf of the following cell at 298 K:
    Cu(s)I Cu2+(0.130M) II Ag+(1.00x10-4M) IAg(s)
    Given E0   Cu2+ /Cu =+0.34 V and E0   Ag+ /Ag =+0.80 V. 
Q: 25) Explain the role of
       1) Cryolite in the electrolytic reduction of alumina
       2) CO  in the purification of nickel
       3) Zinc in recovery of silver.
            
Q: 26) Calculate the depression in freezing point of water when 20.0 g of CH3CH2CHClCOOH is added to 500 g of water.
Given Ka=1.4X10-3,Kf=1.86 Kkg/mol       
Q: 27) What is meant by lanthenoid contraction ?
Discuss the important consequences of lanthenoid contraction.      

Q:28) a) Convert the followings:
          1) Benzene to Benzoic acid
          2) Benzoic acid to benzamide
b) Describe the following with suitable chemical reactions:
        1) Aldol condensation
        2) Cannizzaro reaction                                     
c) Write the IUPAC name of 
          
                          C6H5CH2COCH3
                                                                        Or
a) Convert the followings:
        1) Benzaldehyde to benzophenone
        2) Ethanol to propanone
b) Describe the following with suitable chemical reactions:
        1) Stephen reduction
        2) Gattermann Koch  reaction.
c. Write the IUPAC name of 

                    CH3CHCH3CH2C(CH3)2COCH3 
Q:29) a) Complete  and balance the following chemical equations:
        1)  Br2 +F2 ------------------>
        2) U + ClF3 ------------------>
        3) XeF6+ H2O---------------->

b) Write the reaction for thermal decomposition of sodium azide.
c) Why does PCl3 fume in moisture? 
                                                                       OR
Give the answer of the following:
      1) Draw the structure of XeF4.
      2) Do all bonds in PCl5 alike ?
      3) Why ammonia is a stronger base than phosphine?
      4) White phosphorous is more reactive than red phosphorus.Why?
      5) Thermal stability of water is much higher than that of H2S.Why?
Q:30) a) How can  temperature effect on rate constant be represented quantitatively?

b) The rate constant for a first order reaction is 60/sec.How much time will it take to reduce the initial concentration of the reactant to its 1/16th value? 

                                                                      OR
a) Define order of reation .Derive integrated rate law for 0 order reaction.
b.)  first order reaction takes 40 min for 30% decomposition.Calculate t1/2 for  first order reaction.

Q: 3)
Write  an example of analgesic  and antipyretic drug.
Q: 4)
Out of maltose and sucrose, which is reducing sugar?
Q: 5)
What are ambident  nucleophiles?
Q: 6)
What happen when benzaldehyde react with aniline in acidic medium?
Q: 7)
Give an example of Hoffman bromamide reaction?
Q: 8)
What is chemical Adsorption?

Q: 9)
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 of silver =107.9 u ).
Q: 10)
Explain the following:

      1)  F –centre

      2) A Hole
Q: 11)
Explain the chemistry of lead storage battery  while charging.
Q: 12)
How is disproportionation  takes place in chemical  reactions?
Write a chemical reaction to show disproportionation.
Q: 13)
Explain the formation of Bakelite.
Q: 14)
Give the reasons for:
    1) Haloalkanes though polar ,are insoluble in water.
    2) Grignard reagents should be prepared under anhydrous conditions.
Q: 15)
Describe the functions of antibiotics or  antimicrobials. Give an example.
Q: 16)
Using valency bond theory predict the shape and magnetic behavior  of

[Co(NH3)6]3+ion.
Q: 17)
How will you distinguish between the following chemicals:
     1. Chloroethaneane  and  Bromoethane         
     2. Chlorobenzene and  Chlorocyclohexane
Q: 18)
State Henry‘s law and mention its two important applications .                                                                                           
                                                           OR
Calculate the freezing point of a solution containing 18 g of C6H12O6 ,and 68.4 g of C12H22O11 ,in 200 g water.
The freezing point of pure water is 00C and Cryoscopic Constant of water is 1.86 K/m. 
Q: 19)
Complete the following :
   1. CH3CHCH2NH+HCl  ---------------------------------->   
   2. C6H5N2Cl  +H3PO2+H2O -------------------------------->
   3. C6H5N2Cl  +   C2HOH----------------------------------->
Q: 20)
      1) Write the IUPAC name of  OHCH2CH =CHCH2OH 

      2) Explain the mechanism of hydration of ethene .
Q: 21)
       1) What is nucleoside ?
       2) What are water  soluble vitamins?
       3) Give deficiency diseases of vitamin C and D.       
Q: 22)
Complete and balance the following equations :
       1. F2+H2O(cold) ---------------------------------->
       2. BrO3- +F2+OH---------------------------------->
       3. Ca3P2+ H2O------------------------------------>
                                                                                          OR
       1. PCl+H2O------------------------------------->
       2. KMNO4 +HCl---------------------------------->
       3. S +HNO3--------------------------------------->
Q: 23)
Explain
       1) Freundlich adsorption isotherm.
       2) Shape selective catalysts?Give an example of such catalyst.
Q: 24)
Calculate the emf of the following cell at 298 K:
    Cu(s)I Cu2+(0.130M) II Ag+(1.00x10-4M) IAg(s)
    Given E0   Cu2+ /Cu =+0.34 V and E0   Ag+ /Ag =+0.80 V. 
Q: 25)
Explain the role of
       1) Cryolite in the electrolytic reduction of alumina
       2) CO  in the purification of nickel
       3) Zinc in recovery of silver.
            
Q: 26)
Calculate the depression in freezing point of water when 20.0 g of CH3CH2CHClCOOH is added to 500 g of water.
Given Ka=1.4X10-3,Kf=1.86 Kkg/mol       
Q: 27)
What is meant by lanthenoid contraction ?
Discuss the important consequences of lanthenoid contraction.      

Q:28)
a) Convert the followings:
          1) Benzene to Benzoic acid
          2) Benzoic acid to benzamide
b) Describe the following with suitable chemical reactions:
        1) Aldol condensation
        2) Cannizzaro reaction                                     
c) Write the IUPAC name of
         
                          C6H5CH2COCH3
                                                                        Or
a) Convert the followings:
        1) Benzaldehyde to benzophenone
        2) Ethanol to propanone
b) Describe the following with suitable chemical reactions:
        1) Stephen reduction
        2) Gattermann Koch  reaction.
c. Write the IUPAC name of

                    CH3CHCH3CH2C(CH3)2COCH3 
Q:29)
a) Complete  and balance the following chemical equations:
        1)  Br2 +F2 ------------------>
        2) U + ClF3 ------------------>
        3) XeF6+ H2O---------------->

b) Write the reaction for thermal decomposition of sodium azide.
c) Why does PCl3 fume in moisture? 
                                                                       OR
Give the answer of the following:
      1) Draw the structure of XeF4.
      2) Do all bonds in PCl5 alike ?
      3) Why ammonia is a stronger base than phosphine?
      4) White phosphorous is more reactive than red phosphorus.Why?
      5) Thermal stability of water is much higher than that of H2S.Why?
Q:30)
a) How can  temperature effect on rate constant be represented quantitatively?

b) The rate constant for a first order reaction is 60/sec.How much time will it take to reduce the initial concentration of the reactant to its 1/16th value? 


                                                                      OR
a) Define order of reation .Derive integrated rate law for 0 order reaction.
b.)  first order reaction takes 40 min for 30% decomposition.Calculate t1/2 for  first order reaction.