Solved question paper for Chemistry Mar-2018 (PSEB Class 12th)

Solved Question Paper

Chemistry Mar-2018

PSEB • Class 12th • 1st • Mar-2018

Chemistry previous year question papers on BRpaper help students looking for PSEB 12th Class Question Papers to browse Chemistry papers for board exam practice and revision. This subject section is useful for finding PSEB 12th Chemistry old question papers, PYQ-style papers, and related exam-preparation material where available, so students can study the question format, recurring topics, and marks pattern used in the Punjab board exam. If you are preparing for the Punjab School Education Board Class 12 Chemistry paper, this page can help you compare past question styles with sample paper and model paper trends, and focus on important questions more confidently. BRpaper is not the official website of Punjab School Education Board or any institution, and it does not publish official notices or academic updates.

Solved Questions

Solved
  1. How is benzamide converted into benzylamine? 

    Very Short Answer Mar-2018 • PSEB Class 12th
  2. The chemical name of Vitamin E is ______________ 

    Very Short Answer Mar-2018 • PSEB Class 12th
  3. Soft soaps are potassium salts of higher fatty acids. True/False 

    Very Short Answer Mar-2018 • PSEB Class 12th
  4. Out of 1M urea solution and IM KCl solution, which one has higher freezing point ? 

    Very Short Answer Mar-2018 • PSEB Class 12th
  5. What is Tollen's reagent 

    Very Short Answer Mar-2018 • PSEB Class 12th
  6. Predict the products in the following reaction : 

     

    Very Short Answer Mar-2018 • PSEB Class 12th
  7. What are the units of Rate constant for First Order reaction ? 

    Very Short Answer Mar-2018 • PSEB Class 12th
  8. The class of drugs used for the treatment of cut or wound is :          

    (a) Tranquillizers       (b) Antiseptics       (c) Antihistamins          (d) Antipyretic 

    Very Short Answer Mar-2018 • PSEB Class 12th
  9. Why do transition metals have high enthalpies of atomization ? 

    Short Answer Mar-2018 • PSEB Class 12th
  10. Why does acetylation of -NH, group of aniline reduce its activity ? 

    Short Answer Mar-2018 • PSEB Class 12th
  11. Write two structural differences between DNA and RNA. 

    Short Answer Mar-2018 • PSEB Class 12th
  12. In a metallic oxide, oxide ions are arranged in cubic close packing. One sixth of the tetrahedral voids are occupied by cations P and one third of octahedral voids are occupied by the cation Q.  
     Deduce the formula of the compound.

    Short Answer Mar-2018 • PSEB Class 12th
  13. Explain Mond's process used for refining of nickel. 

    Short Answer Mar-2018 • PSEB Class 12th
  14. [Fe(CN)6]-3 is low spin complex but [Fe(H2O)6]-3  is high spin complex. Explain. 

    Short Answer Mar-2018 • PSEB Class 12th
  15. For a reaction rate law expression is : 
     
    Rate=K[A]1/2 [B]2  
     
    Can the reaction be an elementary ? Explain. 

    Short Answer Mar-2018 • PSEB Class 12th
  16. What are biodegradable polymers ? Give chemical equation for the preparation of any one biodegradable polymer. 

    Long Answer Mar-2018 • PSEB Class 12th
  17. Give reason : 
     
    (a) H3PO4 is triprotic acid but H3PO3, is diprotic acid. Why? 
     
    (b) NCI3 and PC3 are hydrolysed differently. Why? 

    Long Answer Mar-2018 • PSEB Class 12th
  18. Why phenols are acidic in nature ?

    Short Answer Mar-2018 • PSEB Class 12th
  19. (a) What are Etard Reaction and Gattermann Koch Reaction ? Give one example of each.

    Long Answer Mar-2018 • PSEB Class 12th
  20.  Or 
    (a) What are Claisen-Schmidt condensation and Kolbe's Reaction ? Give one example of each. 

    Long Answer Mar-2018 • PSEB Class 12th
  21. NH, and its derivative do not show nucleophillic addition reactions with aldehydes and      ketone in high acidic medium. Justify. 

    Long Answer Mar-2018 • PSEB Class 12th
  22. (a) Analysis shows nickel oxide has the formula Ni0.93 O1.00 What fraction of Ni exists as  Ni3+  and Ni2+  ions in given oxide ?  
     
    (b) Explain metal deficiency defect due to cation vacancies. 

    Long Answer Mar-2018 • PSEB Class 12th
  23. (a) When HgI2 is added to aqueous solution of KI, why there is an increase in osmotic pressure of solution ? Commercially available HCl contains 38% HCl by mass. 
     
     

    Long Answer Mar-2018 • PSEB Class 12th
  24. (a) Give two differences between macromolecular colloids and associated colloids. 
     
    (b) Explain the term dialysis. How can it be increased ? 

    Long Answer Mar-2018 • PSEB Class 12th
  25. (a) Explain Normal or Standard hydrogen electrode.  
     
    (b) How much amount of substance is deposited by passing one Faraday of electricity ? 

    Long Answer Mar-2018 • PSEB Class 12th
  26. Or 
     
    Calculate the cell potential (EIN) of the following cell at 298K. 
     
    Ag(s) | AgNO3 (0.01M) || AgNO3 (1.OM) Ag(s

    Long Answer Mar-2018 • PSEB Class 12th
  27. (a) Why do Zr and Hf have similar properties? 

    Long Answer Mar-2018 • PSEB Class 12th
  28. What happens when K2Cr2O7, is treated with H2SO4 and NaCl solution ?

    Long Answer Mar-2018 • PSEB Class 12th
  29. Why Transition metals form alloys easily? 
     
                                      Or 
     

    Long Answer Mar-2018 • PSEB Class 12th
  30. What happens when K2Cr2O7 is heated strongly ?  

    Long Answer Mar-2018 • PSEB Class 12th
  31. Transition elements form complexes easily ? Justify

    Long Answer Mar-2018 • PSEB Class 12th
  32. Why 5d transition series elements have higher ionization enthalpies than 4d transition series elements ? 

    Long Answer Mar-2018 • PSEB Class 12th
  33. (a) Explain with example Sy mechanism

    Long Answer Mar-2018 • PSEB Class 12th
  34. Dipole moment of chlorobenzene is lower than that of cyclohexylcholoride. Give reason. 
     
                                                                 Or 

    Long Answer Mar-2018 • PSEB Class 12th
  35. How will you convert the following ? 
     
    (a) Ethyl bromide to Ethylisocyanide  
    (b) Isopropylbromide to Propene  
    (c) Aniline to Flourobenzene 
    (d) Chlorobenzene to D.D.T. 

    (e) Bromoethane to iodoethane. 
    (f) Chlorobenzene to Aniline.

    Long Answer Mar-2018 • PSEB Class 12th
  36. (a) Why CIF3 exists but FCl3 does not? 
          (b) Why ICl3 is more reactive than l2?  
          (c) Using VBT theory describe the shape of XeO4

    Long Answer Mar-2018 • PSEB Class 12th
  37.  Or 

    (a) Why does Fluorine shows anomalous behavior ?  
    (b) Why sulphuric acid is oily and viscous liquid ?  
    (c) What happens when Cu reacts with cold dilute HNO3 ?

    Long Answer Mar-2018 • PSEB Class 12th

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FAQ

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Answers about this subject, solved papers, and preparation.

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01 How can I find PSEB 12th Chemistry previous year question papers for 1st semester on BRpaper?

Open the Chemistry subject page under PSEB 12th Class Question Papers and use it to browse available Chemistry previous year papers for 1st semester revision and board-style practice.

02 Can this Chemistry page help me understand the PSEB Class 12 paper pattern?

Yes. Students often use previous Chemistry papers on this page to review question style, section flow, recurring topic areas, and the overall structure seen in past Punjab board exams.

03 Are previous year Chemistry papers useful along with sample paper or model paper practice?

Yes. Previous year papers show real past exam style, while sample or model papers are commonly used for extra pattern-based practice. Using both can help with revision and time-based preparation.

04 Can I use past Chemistry papers to identify important questions and repeated topics?

Past papers are often used to spot commonly tested areas in Chemistry, such as numericals and questions from organic, inorganic, or physical chemistry. They are helpful for setting revision priorities, not for guaranteeing exact repeats.

05 Does this page include solved Chemistry papers or answer keys?

This subject page is mainly for browsing previous year Chemistry question papers. If solution-based practice is available anywhere on the site, students should verify it on the page instead of assuming all papers include answers.

06 How should I prepare for the Chemistry exam in limited time using previous papers?

Start by reviewing a few past Chemistry papers to understand the question pattern, then revise the chapters that appear frequently, practice numericals, and use the papers for timed self-testing before the exam.