Top 10 questions in chemistry cbse class 12 exam 2020

Top 10 Questions in Chemistry CBSE Class 12 Exam - 2020

Check top 10 important chemistry questions and answers that will help you plan your study and revision in CBSE Class 12 Chemistry exam - 2020

By Topperlearning Expert 28th Feb, 2020 | 04:42 pm

The CBSE Class 12 Chemistry examination is scheduled on 7^th March 2020 which means there are very few days left. The Chemistry paper is divided into 4 sections—A, B, C and D. All the sections add up to 70 marks. Students get 3 hours to write the paper. The paper is full of options and based entirely on the guidelines set by NCERT.

Based on the research done by our in-house SMEs, we have created a list of important questions that students should focus on during their revision. These important questions for CBSE Class 12 Chemistry are as follows:

Important Questions & Answers CBSE Class 12 Board Exam 2020 : Chemistry

1. Write the IUPAC names of the following coordination compounds:

(i) [Cr(NH₃)₃Cl₃]

(ii) K₃[Fe(CN)₆]

(iii) [CoBr₂(en)₂]+ (en = ethylenediamine)

Solution:

IUPAC Nomenclature:

(i) Triamminetrichlorochromium (III)

(ii) Potassium hexacyanoferrate (III)

(iii) Dibromidobis (ethane-1, 2-diammine) cobalt (III) ion

2. A solution containing 15 g urea (molar mass = 60 g mol^-1) per litre of solution in water has the same osmotic pressure (Isotonic) as a solution of glucose (molar mass = 180 g mol^-1) in water. Calculate the mass of glucose present in one litre of its solution.

3. Write the chemical equations to illustrate the following name reactions:

(i) Rosenmund reduction

(ii) Cannizzaro's reaction

(iii) Aldol condensation

4. Define the following:

(i) Schottky defect

(ii) Frenkel defect

(iii) F-centre

5. Give reasons for the following:

(i) (CH₃)₃P = O exists but (CH₃)₃ N = O does not.

(ii) Oxygen has less electron gain enthalpy with negative sign than sulphur.

(i) H₃PO₂ is a stronger reducing agent than H₃PO₃.

6. Write the structures of the main products when benzene diazonium chloridereacts with the following reagents:

(i) CuCN/KCN

(ii) H₂O

(iii) CH₃CH₂OH

7. Differentiate between the following:

(i) Essential amino acids and non-essential amino acids

(ii) Fibrous and globular proteins

8. Write the names and structures of the monomers of the following polymers:

(i) Nylon-6

(ii) Novolac

(iii) Buna-N

(iv) Teflon

(v)Melamine

9. Write the therapeutic action of the following on the human body and mention the class of drugs to which each of these belong.

(i) Ranitidine

(ii) Aspirin

(iii) Morphine

10. (i) Calculate emf of the following cell at 25°C:

Sn | Sn²⁺ (0.001 M) || H⁺ (0.01 M) | H_2(g) (1 bar) | Pt_(s)

(ii) Calculate D_rG^O for the reaction:

Mg_(s) + Cu²⁺_(aq) --------- Mg ²⁺_(aq) + Cu_(s)

Given: E⁰ _cell= + 2.71 V, 1 F = 96500 C mol^-1

For reviewing all the important answers and practice material for CBSE Class 12 Chemistry exam 2020 click here:

CBSE Class 12 Chemistry exam 2020 - Sample Papers

CBSE Class 12 Chemistry exam 2020 - Previous years papers

CBSE Class 12 Chemistry exam 2020 – Most important questions

CBSE Class 12 Chemistry exam 2020 – Text book solutions

CBSE Class 12 Chemistry exam 2020 – Chapter wise practice test

Important topics for your reference:

Top 10 Questions in Physics CBSE Class 12 Exam - 2020

6 Useful subject-specific tips for CBSE Class 12 Science exam preparation - 2020

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