A compound A of molecular formula C2H3OCl undergoes a series

Subject

Chemistry

Class

CBSE Class 12

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Sample Papers

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 Multiple Choice QuestionsShort Answer Type

21.

How do you convert the following:

(i) C6H5CONH2 to C6H5NH2

(ii) Aniline to phenol

(iii) Ethanenitrile to ethanamine

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22.

Write the chemical equations involved when aniline is treated with the following reagents:

(i) Br2 water
(ii) CHCI3 + KOH
(iii) HCl

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23.

Write the names and structures of the monomers of the following polymers:
(i) Buna-S
(ii) Glyptal
(iii) Polyvinyl chloride

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24.

(i) Write the product obtained when D-glucose reacts with H2N - OH.
(ii) Amino acids show amphoteric behaviour. Why?
(iii) Why cannot vitamin C be stored in our body?

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25. Write the structure of the major product in each of the following reactions:



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26.

Give reasons for the following:
(i) Phenol is more acidic than ethanol.
(ii) The boiling point of ethanol is higher in comparison to methoxymethane.
(iii) (CH3)3C - O - CH3 on reaction with HI gives CH3OH and (CH3)3C -I as the main products and not (CH3)3C -OH and CH3I.

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27.

Seeing the growing cases of diabetes and depression among young children, Mr Lugani, the principal of on reputed school organised a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr Lugani conducted the health survey is most of the schools and discovered a tremendous improvement in the health of the students.
After reading the above passage, answer the following questions:

(i) What are the values (at least two) displayed by Mr Lugani?
(ii) As a student, how can you spread awareness about this issue?
(iii) What are antidepressant drugs? Give an example.
(iv) Name the sweetening agent used in the preparation of sweets for a diabetic patient.

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 Multiple Choice QuestionsLong Answer Type

28.

(a) Account for the following:

(i) Zr and Hf have almost similar atomic radii.

(ii) Transition metals show variable oxidation states. 

(iii) Cu+ ion is unstable in aqueous solution.

(b) Complete the following equations:

(i) 2 MnO2 + 4 KOH + O2--->

(ii) 2 Na2CrO4 + 2 H + -->

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29.

 bold E subscript bold M to the power of bold 2 bold plus end exponent bold divided by bold M end subscript superscript bold 0

Cr

Mn

Fe

Co

Ni

Cu

-0.91

-1.18

-0.44

-0.28

-0.25

-0.34


From the given data of E0 values answer the following Question:

(i) Which is strongest why is  value exceptionally positive?

(ii) Why is value highly negative as compared to other elements?

(iii) Reducing agent  Cr2+ or Fe2+? Give reason

 

(b) Why do actinoids show wide range f oxidation states? Write on the similarity between the chemistry of lanthanoids and actinoids.

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30.

 A compound 'A' of molecular formula C2H3OCl undergoes a series of reactions as shown below. Write the structures of A, B, C and D in the following reactions:

 

 

(b) Distinguish between the following:

(i) C6H5-COCH3 and C6H5 - CHO

(ii) Benzoic acid and methyl benzoate

(c) Write the structure of 2- methylbutanal.


(a) Using the given molecular formula, compound A is Ethanoyl Chloride CH3COCl, which undergoes reaction with poisoned palladium.
On carrying hydrogenation of A in the presence of poisoned palladium, we get an aldehyde. Hence, B can be Ethanal, CH3CHO.
An aldehyde, on treating with dilute alkali, undergoes aldol condensation reaction. Hence, C can be CH3CH (OH) CH2CHO.
On heating an aldol product, it loses water to produce a double bond and we get CH3CH=CHCHO.
Hence, we have

 

(b)
(i) Acetophenone has methyl group attached to carbonyl carbon while benzaldehyde does not. Therefore, we can use iodoform test to distinguish between the two. Acetophenone will undergo iodoform test and give a yellow precipitate.

C6H5-COCH3    C6H5COOH + CHI3

Acetophenone                           (yellow ppt.)

 

C6H5CHO    No reaction

Benzaldehyde

(ii) Benzoic acid can react with sodium bicarbonate to give brisk effervescence due to the release of CO2, while methyl benzoate does not.

C6H5COOH + NaHCO3----> C6H5COONa + H2O + CO2

Benzoic acid                                               (brisk effervescence)

 

C6H5COOCH3 + NaHCO3---> No reaction

Methyl benzoate

 

(c) The Structure of 2- methylbutanal is:

 

 

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