CBSE Term 1 Class 12 Chemistry Marking Scheme & Sample Paper: CBSE Board Exam 2021-22

Check CBSE Term 1 Class 12 Chemistry Marking Scheme & Sample Paper. Download now and prepare for CBSE Term 1 Class 12 board exam 2021-22.

Created On: Nov 8, 2021 19:02 IST
Modified On: Nov 9, 2021 15:34 IST
CBSE
CBSE

Check CBSE Term 1 Class 12 Chemistry Marking Scheme & Sample Paper for upcoming CBSE 12th Chemistry board exam. With these resources students can easily learn about the new exam pattern and important concepts on which questions are expected in the exam.

CBSE 10th & 12th Board Exam 2021-22: Check CBSE OMR Sheet & Important Instructions

CBSE Term 1 Class 12 Chemistry Marking Scheme & Sample Paper 2021-22: 

SECTION A

This section consists of 25multiple choice questions with overall choice to attempt any 20

questions. In case more than desirable number of questions are attempted, ONLY first 20 will

be considered for evaluation.

1. Which of the following statements is true:

(a) Melting point of Phosphorus is less than that of Nitrogen

(b) N2 is highly reactive while P4 is inert

(c) Nitrogen shows higher tendency of catenation than P

(d) N-N is weaker than P-P

Answer:

1.(d) N-N is weaker than P-P other statements as incorrect as Phosphorus has a higher melting point due to bigger size than Nitrogen. Nitrogen is inert due to formation of triple bonds and has a lower covalence due to non - availability of d –orbitals.

2. Which of the following is a non-stoichiometric defect?

(a) Frenkel defect

(b) Schottky defect

(c) metal deficiency defect

(d) interstitial defect

Answer:

2. (c)metal deficiency defect (anion is missing from lattice site)

In Frenkel defect the smaller ion occupies the interstitial sites and Schottky defect equal number of cations and anions are missing. Interstitial defect an atom or molecule occupies intestinal sites so in these three defects the ratio of positive and negative ions (Stoichiometric) of a solid is not disturbed in these three.

3. Identify the law which is stated as:

“For any solution, the partial vapour pressure of each volatile component in the solution is

directly proportional to its mole fraction.”

(a) Henry’s law

(b) Raoult’s law

(c) Dalton’s law

(d) Gay-Lussac's Law

Answer:

3. (b) Raoult’s law

4. Pink colour of LiCl crystals is due to:

(a) Schottky defect

(b) Frenkel defect

(c) Metal excess defect

(d) Metal deficiency defect

Answer:

4. (c) Metal excess defect (formation of F centres)

5. Which of the following isomer has the highest melting point:

(a) 1,2 - dicholorbenzene

(b) 1,3 - dichlorobenzene

(c) 1,4 - dicholorbenzene

(d) all isomers have same melting points

Answer:

5. (c) 1,4-dicholorbenzene ( para isomers are more symmetric and ortho and meta )

6. Which one of the following reactions is not explained by the open chain Structure of glucose:

(a) Formation of pentaacetate of glucose with acetic anhydride.

(b) formation of addition product with 2,4 DNP reagent

(c) Silver mirror formation with Tollen’s reagent

(d) existence of alpha and beta forms of glucose. 

Answer:

6. (d) existence of alpha and beta forms of glucose .

7. Williamson’s synthesis of preparing dimethyl ether is an:

(a) SN1 reaction

(b) Elimination reaction

(c) SN2 reaction

(d) Nucleophilic addition reaction

Answer:

7. (c) SN2 reaction (alkoxide ion reacts with primary alkyl halide in a single step to form ether)

8. Chlorine water loses its yellow colour on standing because:

(a) HCl gas is produced, due to the action of sunlight.

(b) a mixture of HOCl and HCl is produced in the presence of light

(c) HOCl and hydrogen gas is produced

(d) a mixture of HCl and ClO3 is produced, due to the action of sunlight

Answer:

8. (b) a mixture of HOCl and HCl is produced in the presence of sunlight

Cl2(g) +H2O (l)  HCl (g) +HOCl(aq)

9. During dehydration of alcohols to alkenes by heating with concentrated H2SO4, the initiation step is:

(a) protonation of alcohol molecule

(b) formation of carbocation

(c) elimination of water

(d) formation of an ester

Answer:

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For all the questions & their answers, download the PDF from the following links

CBSE Class 12 Chemistry Sample Paper 2021-22 (Term 1) PDF

CBSE Class 12 Chemistry Marking Scheme 2021-22 (Term 1) PDF

 

 

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