CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved

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Class 12 Chemistry Solved Question Papers: CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved

Access comprehensive previous year question papers for Class 12 Chemistry using the CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved. Designed to align with the 2026-27 CBSE academic guidelines, these solved papers help students assess their exam readiness and understand official marking schemes.

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1. What type of magnetism is shown by a substance if magnetic moments of domains are arranged in same direction?
 
2. Draw the structure of 4-tertbutyl-3-iodoheptane. 
 
3. Arrange the following in decreasing order of basic strength in gas phase:
C2H5NH2 , (C2H5)2NH, (C2H5)3N , NH3
 
4. Write the structure of the following:
4-fluoro-2-hydroxyacetophenone
 
5. Give the equation of reaction for the preparation of phenol from cumene. 
 
6. Explain the following:
i) Henry’s law about dissolution of a gas in a liquid
ii) Boiling point elevation constant for a solvent.
 
7. Explain the following observations:
i) Transition metals generally form coloured compounds.
ii) The highest oxidation state of a metal is exhibited in its oxide or fluoride.
What happens when KI solution is added to
i) Alkaline solution of KMnO4?
ii) Acidified solution of KMnO4?
 
8. Explain the following terms:
i) Electrophoresis
ii) Dialysis
 
9. For a certain reaction, variation in the concentration, ln[R] Vs time(s) plot is given below:
CBSE Class 12 Chemistry Question Paper 2020 Set D Solved 1
 
i) What is the order of the reaction?
ii) What are the units of rate constant k?
iii) Give the relationship between k and t1/2?
iv) What does the slope of the above line indicate?
 
10. What happens in the following activities and why?
i) An electrolyte is added to a hydrated ferric oxide sol in water.
ii) A beam of light is passed through a colloidal solution.
 
11. The density of chromium metal is 7.2 g cm-3. If the unit cell has edge length of 289 pm, determine
i) The type of unit cell
ii) The radius of chromium metal
(At.mass of Cr = 52 u, N0= 6.023 x 1023 )
 
12. Describe the preparation of potassium permanganate from pyrolusite ore. Write balanced chemical equation for one reaction to show the oxidizing nature of potassium permanganate.
 
13. Give reasons for the following observations:
i) p-dichlorobenzene has higher melting point than those of o and m –isomers.
ii) Haloarenes are less reactive than haloalkanes towards nucleophillic substitution reaction.
iii) The treatment of alkyl chloride with aqueous KOH leads to the formation of alcohol but in the presence of alcoholic KOH, alkene is the major product.
 
14. Assuming complete ionization, calculate the expected freezing point of solution prepared by dissolving 7.00g of Glauber’s salt, Na2SO4.10H2O in 100 g of water.
(Kf for water = 1.86 K kg mol-1)(RAM of Na = 23, S = 32 , O = 16, H =1 u)
 
15. How are the following conversions carried out?
i) Ethanoic acid to methanamine
ii) Nitromethane to dimethyl amine
iii) Chlorobenzene to p-chloroaniline
 
16. i) Name the method used for refining of zirconium.
ii) What is the role of CO in the extraction of iron?
iii) What is meant by the term pyrometallurgy?
 
17. Write the mechanism of the following reaction :
 
                    H+
2CH3CH2OH   →  CH3CH2-O-CH2CH3
 
18. A first order reaction takes 40 minutes for 30% decomposition. Calculate t1/2 for this reaction.
OR
Consider the reaction : 2A + B → C + D
Following results were obtained in experiments designed to study the rate of reaction:
CBSE Class 12 Chemistry Question Paper 2020 Set D Solved 2
i) Write the rate law for the reaction.
ii) Calculate the value for the rate constant for the reaction.
 
19. i) What type of linkage holds together the monomers of DNA?
ii) What are the expected products of hydrolysis of lactose?
iii) What happens when D-glucose is treated with
a) HI
b) HNO3
 
20. i) Write the formula for the following coordination compound:
Amminebromidochloridonitrito-N-platinate(II)
ii) Why is geometrical isomerism not possible in tetrahedral complexes having two different types of unidentate ligands coordinated with the central metal ion?
iii) On the basis of crystal field theory, write the electronic configuration of d4 ion if Δt> p.
 
21. Account for the following :
i) XeF2 is linear molecule without a bend.
ii) The electron gain enthalpy with negative sign for fluorine is less than that of chlorine, still
fluorine is a stronger oxidizing agent than chlorine.
iii) Nitrogen shows catenation properties less than phosphorous.
 
22. i) Classify the following as addition and condensation polymers:
Terylene, Bakelite, Polyvinyl chloride, Polythene.
ii) Explain the difference between Buna – N and Buna – S.
 
23. Natural sweeteners, eg; sucrose add to calorie intake and therefore, cannot be used by diabetic patients. Such people use saccharin, alitame, aspartame as artificial sweeteners. These are boon for people who want to control their calorie intake.
i) Why is the use of aspartame limited to cold food and soft drinks?
ii) What is the drawback of alitame?
iii) Which is a better artificial sweetener than alitame and why?
iv) What are the values possessed by people taking less sugar?
 
24. i) Draw the structure of the following compounds:
a) XeF4
b) H3PO4
ii) Assign reasons for the following :
a) SF6 is kinetically inert.
b) NF3 is an exothermic compound whereas NCl3 is not.
c) HCl is a stronger acid than HF though fluorine is more electronegative than chlorine.
OR
i) How is ammonia prepared on a large scale? Name the process and mention the optimum conditions for the production of ammonia by this process.
ii) Complete the following chemical equations :
a) NH4Cl (aq.)+ NaNO2 (aq. ) →
b) P4 + 3NaOH + 3H2O →
iii) Why is Ka2<< Ka1 for H2SO4 in water?


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Where can I download the official PDF for CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved?

The CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved is available for download on StudiesToday.com. It includes complete set with all sections so that Class 12 students can practice with the exact same paper that came in the CBSE exams.

Are the solutions for CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved based on the official CBSE marking scheme?

Yes, the solutions for CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved are prepared by subject matter experts as per official marking scheme. Class 12 students will understand the structure of answers and 'step-marks' methodology Chemistry.

How does solving CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved help in preparing for the 2026 exams?

Solving previous year papers like CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved is important to understand repeat themes and question difficulty levels of Chemistry. It helps Class 12 students to test their time management skills too.

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Yes, where applicable, CBSE Class 12 Chemistry Question Paper 2020 Set 04 Solved is available in both English and Hindi mediums. All students from Class 12 can access Chemistry study material in their preferred language.

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