VST on CHSE - Class XII

If you are preparing to appear in Council of higher secondary education, Odisha, you must at least look into these super selective questions on the topics Electrochemistry, Chemical kinetics, Alkyl and Aryl halides, Alcohol Phenols and Ethers, Aldehyde, Ketone and Carboxylic acids.

1.Answer all questions. [1X7=7]

i.In which order reaction the unit of rate and rate constant is same?

a.Zero                

b.First                  

c.fractional                 

d.second

ii.Which of the following can affect the value of rate constant.

a.concentration   

b.temperature      

c.catalyst        

d.both b. and c.

iii.The rate constant of a first order reaction, K = 1050 exp (-10) at 100K. The activation energy in J mol^-1 is:

a.1050                      

b.10                       

c.8314                

d.100

iv.3 Faradays of electricity will deposit what amount of Aluminum (in gram) from molten Al₂O₃.

a.3             

b.27             

c.3X96500 

d.3X27                 

v.The standard electrode potential of SHE is taken as:

a.1.2V                  

b.1.0V                  

c.0.0V                  

d.0.3V

vi.Ethylene reacts with HBr and then undergoes Wurtz reaction . The product formed is:

a.butane    

b.propane 

c.ethylbromide   

d.ethylcyanide

vii.The major product formed when Benzene and 1-chloropropane undergo F.C alkylation is:

a.propylbenzene          

b.chlorobenzene   

c.isopropylbenzene               

d.acetophenone

2.Answer all the questions [1X7=7]

i. If r = K[A][B]^1/2, then the partial order w.r.t. B is ________.

ii. As the dilution increases, the specific conductance ______.

iii. IUPAC name of isopropylalcohol is ______.

iv. The reagent for Clemensen’s reduction is _________.

v. Benzyl alcohol on oxidation with K₂Cr₂O₇/ H₂SO₄ gives _____.

vi. Formula of urotropine is ________.

vii.Alcohols on oxidation with strong oxidizing agent give _____.

3. Answer any seven [2X7=14]

i. Define order of reaction and give one example each of zero and first order reaction.

ii.The molar conductance of 1.0 M solution of an electrolyte is 100 S cm² mol^-1 . Calculate its specific conductance.

iii. Write Nernst’s equation for the following half cell reaction:

Fe²⁺ + 2e^- ---------> Fe

iv. Predict the products obtained on electrolysis of aqueous silver nitrate using silver electrodes.

v. How can you distinguish between acetaldehyde and acetophenone?

vi. How can you prepare chlorobenzene from benzene diazonium chloride?

vii. What is HVZ reaction?

viii. What happens when the aldol formed from acetaldehyde is heated?

ix. Benzene reacts with nitrating mixture (HNO₃ + H₂SO₄) to form A which on reduction with Sn/HCl gives B. What are A and B?

4. Answer any seven [3X7=21]

i. What is secondary cell? Discuss lead storage cell.

ii. Derive the relationship between equivalent and specific conductance.

iii. Calculate the normality of KCl solution having resistance 1000 Ohm. The cell constant is 5.0 cm and the equivalent conductance is 150 ohm^-1cm² eq^-

iv.What is Fehling solution? Write its use

v.How can a carboxylic acid be converted to an aldehyde in two steps?

vi. How does acetone react with Grignard’s reagent?

vii. What happens in aldol condensation?

viii. How can you introduce a keto group into an aromatic nucleus? Give equation.

ix.Discuss Etard’s reaction.

Group D

Answer any three [7 X 3 = 21]

5. Write short notes on:

a. Activation energy

b.Half life period

6. Discuss Kohlrausch’s law and Electrochemical series

7.Give two methods of preparation of acetaldehyde and how does it react with : a. NaHSO₃      b.Hydroxylamine         c.Tollen’s reagent

8.Write two methods of preparations of phenol. How can you get salicylaldehyde from it? Arrange para nitro phenol, phenol and para cresol in increasing order of their acidity.

9. What do you mean by organic reduction? Write short notes on:

a. Bouveault Blanc reduction

b.Meerwein ponndorf verly reduction

c.Wolff kishner reduction

d.Rosenmund’s reduction

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