UP Board Question Paper 2011
Subject: Chemistry (Second Paper)
Class : XII
375(PH)
(General and Inorganic Chemistry)
(Only for Science Groups and Commercial Groups)
Time: 3 Hours                                                                         Marks: 35

General Instruction:

i. All questions are compulsory. Marks allotted to each question are given in the margin.
ii. Give relevant answers to the questions.
iii. In numerical questions, give all the steps of calculation.
iv. Give chemical equations wherever necessary.

1. There are four alternatives for each part of this question. Select the correct alternative and write it in the answer book.

a) The pH value of 1.0 X 10^-8 M NaOH solution is

              i) 6             ii) 7                 iii) 8             iv) 14.                                               1

b) The most effective substance for bringing about coagulation of positively charged sol is

            i) CuSO₄         ii) C₂H₅OH      iii) AlCl₃       iv) K₄[Fe(CN)₆].                                 1

c).Which of the following reactions pseudo-unimolecular.

       i). CH₃COOC₂H₅+NaOH→CH₃COOC₃Na+C2H₅OH

       ii). CH₃COOCH₃ → H₂O -----^H-→ CH₃COOH+CH₃OH

      iii). 2FeCl₃+SnCl₂→2FeCl₂+SnCl₄

      iv). H₂+Cl₂→2HCl.                                                                                            1

2.a). Give the relationship as will as well as difference between solubility and solubility product of any binary electrolyte solution.                                                    2

   b) Explain example what you men by the heat of formation.                                                             1

3.a). State Le-Chatelier’s principle. What would be the effect of pressure and temperature on the following equilibrium?

                          2SO₂(g)+O₂(g) ↔ 2So₃(g)+heat.                                                                                   1

  b). 11.7 gm sodium chloride is dissolved in 500 ml water. Calculate the molarity of the solution.

            [Na=23, Cl=35.5]                                                                                                                        1

4. a).Clarify the difference between suspension colloidal solution.                                                    1

    b). What is enzyme catalysis? Give the name of any one enzyme catalyst.                                    1

    c). Explain distribution law.                                                                                                            1

5. a) Four alternatives are given for each part of this question. Select the correct alternative and write it in your answer-book:

         x) The compound formed by the dehydration of glycerol is

             i) Propanone           ii) Formic acid           iii) Acrolein             iv) Allyl alcohol.                               1

         y) Which of the following diseases is caused by the deficiency of iodine?

            i) Beri-beri                 ii) Scurvy                   iii) Night Blindness   iv) Goitre.                                    1

b) Write the names of following compounds in I.U.P.A.C. system:

i)                    Cl     O                                                                              1/2

                      |     ||

           CH₃ ― CH ― C ― CH₂―CHO

ii)                           CH_{3                                                                          1/2}

                               |

             CH₂ = CH ― C ― CH₃

                               |

                             C₃H₇

c) What is Metamerism? Explain with example.                                1

6. a) With the help of one chemical reaction each, prove that glucose has one aldehyde and five – OH groups.             2

    b) A dibasic organic acid has 26.67% carbon and 2.22% hydrogen. 1.125 gm acid is dissolved in water and the volume of the solution is made up to 250ml. 27.5 ml of N/11 NaOH is used for complete neutralization of 25ml of this solution. Determine the molecular formula of the acid.                                                     3

                 (C = 12, H = 1, O = 16)

7. a) Giving an example in explain the importance of chromatography in the purification of organic compounds.        2

    b) Write a note on knocking.                                                                           1

    c) Explain the stability of tertiary carbonium ion.                                           1

8. a) What happens when –

        (Give chemical question only)

     i) Acetone is heated with iodine and sodium hydroxide?

    ii) Phenol is heated with chloroform and caustic soda solution?               1+1

   b) How will you obtain the following?

       (Give chemical question only)

      i) D.D.T. from chlorobenzene

     ii) Picric acid from benzene.                                                       1+1

9. a) Complete the following:                                                             2

i)       CH

        |||

        CH -----^{(H3O+), Hg+}-→ A ----^{Dil. NaOH}----→ B

ii)        CHCl3 ------^A---→ CH ----^HBr---→ B.

                                      |||

                                      CH

b) How will you obtain secondary alcohol by Grignard reagent? Give equation.                                1

10. Describe with diagram the laboratory method for the preparation of formaldehyde. What happens when formaldehyde is heated with caustic soda? Also give equation for the reactions involved.

                                         OR

Describe the industrial method for manufacture of ethyl alcohol from starch. Give the equations for chemical reactions involved. What is power alcohol?                                        3

Index Question Paper Class XII