Aldehydes Ketones and Ethers(12 Std):- Important and conceptual questions

Aldehydes Ketones and Ethers:- Important and conceptual questions

Answers are given in the end-

1. Why does carbonyl compounds give Nucleophylic reaction?

2. Arrange the following carbonyl compounds in increasing order of their reactivities towards nucleophylic addition reaction.

CH₃CHO, HCHO, CH₃COCH₃

3.Which of the following compounds give iodoform reaction and why?

CH₃CHO, HCHO, CH₃CH₂COCH₂CH₃

4 Which of the following compounds give cannizaro,s reaction and why?

CH₃CHO, HCHO, CH₃CH₂COCH₂CH₃

5. Which of the following compounds give aldol condensation reaction and why?

CH₃CHO, HCHO, CH₃CH₂COCH₂CH₃

6. How many compounds are formed in the cross aldol condensation of

A) CH₃CHO, CH₃COCH₃

B) Ph-CHO and CH₃CHO

C) Ph-CO-Ph and CH₃CHO

D) CH₃COCH₃and CH₃CH₂COCH₂CH₃

E) Ph-CHO and Ph-CO-Ph

7.What are the disproportion reaction. Give example.

Answer-

1. Nucleophylic reaction reaction occure due to presence of partial positive charge on carbonyl carbon and addition reaction occure due to presence of double bond.

2. CH₃COCH₃< CH₃CHO < HCHO

3. CH₃CHO, The compounds have three alpha hydrogen atoms to carbonyl groups gives iodoform reaction.

4. HCHO, The compounds have no any alpha hydrogen atoms to carbonyl groups gives cannizaro,s reaction.

5. CH₃CHO and CH₃CH₂COCH₂CH₃The compounds have atleast one alpha hydrogen atoms to carbonyl groups gives aldol condensation reaction.

6. A) Four aldol products

B) Two aldol products

C)Two aldol products

D) Four aldol products

E) No aldol products

7. The reaction in which same species is oxidized and reduced simultaneously.

Example is cannizaro,s reaction in which carbonyl compounds having no alpha hydrogen is oxidized in carboxylate ion and reduced to alcohol.

Ph-CHO + KOH à Ph-COO^– + Ph-CH₂-OH

Biomolecules (XII Std)-Important and conceptual Questions

Answer are given in the end–

Questions useful in Board Examination.

1.What is basic unit of carbohydrates?

2.What is basic unit of protein or polypeptide?

3.What is the non reducing sugar and what is cause of it?

4.What do you mean primary structure of protein ?

5. What do you mean secondary structure of protein ?

6.What do you mean tertiary structure of protein ?

7.What is native structure of protein?

8.What is zwitter ion.

9.Which vitamins are fat soluble?

10.What is importance of primary structure of protein?

Answers-

1.Glycosidic Linkages

2.Peptide bond

3.The sugar which reduces Tollen,s reagents or Fehling,s solution is called reducing sugar. It is because their carbonyl functions are not free.

4.The specific sequence of amino acid in protein is called primary structure of protein.

5.Alpha halix or beta pleated sheet are secondary structure of protein which is stabilized by hydrogen bonds. alpha helix is a helical structure whereas beta pleated sheet is formed by placing primary structure sidewise.

6.Tertiary structure of protein is formed by overlapping and folding of primary and secondary structure of over each other. Tertiary structure is stabilized by following bonds-
1) Hydrogen bond formed between -NH₂ group and C=O group of different part of polypeptide chain.
2) Ionic bond formed between -NH₃⁺ and COO^– groups of different part of polypeptide chain.
3) Disulphide bond -S-S- between different part of polypeptide chain.
4) Hydrophobic bond is not actual type of bond but it is a condition in which nonpolar hydrophobic chains moves inside the protein.

7. The original and active shape of protein at particular pH range and temperature range is called native state of Protein.

8.The bipolar ion of amino acid is called zwitter ion.

9.Vitamins A , D , E and K are fat soluble.

10.The change only in one amino acid in polypeptide chain changes property also. Example-In sickle cell anemia is an inherited disease which affect red blood cell and change it into sickle shaped. It is due to change in only one amino acid i.e. glutamic acid by valine in the polypeptide chain making hemoglobin.

Electrochemistry(XII Std) Important Questions Answers

Answers are given in the end

1.What is NFE/SHE ?

2.Explain the variation of conductivity with dilution. or How does conductivity varies with dilution ? Explain the reason for the variation ?

3.Explain the variation of molar conductivity of weak electrolyte with dilution. or How does conductivity of weak electrolyte varies with dilution ? Explain the reason for the variation ?

4.Explain the variation of molar conductivity of strong electrolyte with dilution. or How does conductivity of strong electrolyte varies with dilution ? Explain the reason for the variation ?

5.Explain Kohlrausch law

6.Calculate the Vont hoff’s factor for K₄[Fe{CN)₆] .

7.What is cell constant ?

8.Why can’t molar conductivity at infinite dilution of weak electrolyte be measured using graphical method ?

9.What are the secondary cells?

10. What are the fuel cells?

11.State advantages and disadvantages of fuel cells.

Answers- 1.The hydrogen electrode at 298 K with pressure of hydrogen is 1 bar and concentration of hydrogen is 1 M is called Standard Hydrogen Electrode / Normal Hydrogen Electrode. 2.Conductivity decrease with dilution because number of ions decreases per unit volume with dilution. ( Conductivity is the conductance of solution of unit volume/ one litre. 3. Molar conductivity of weak electrolyte increases with dilution due to increase in degree of dissociation. 4.Molar conductivity of strong electrolyte increases with dilution due to decrease in interionic attraction as interionic distance increase with dilution. 5.At infinite dilution molar conductivity of weak electrolyte is sum of contribution of molar conductivities of cations and anions which are independent of each other. 6. Von,t Hoff factor = 5/1 =5. 7. Cell constant is the ratio of length between vs area of electrode = L / A 8.Because line of graph never touch molar conductivity axes. 9.The cell which can be reuse again and again by charging. 10. The cell which generate energy from fuel without burning it , is called fuel cell. 11. Advantage of fuel cell-(1) It is pollution free (2) Continuous source of electricity (3) byproduct is water. Disadvantages of fuel cell- It is costly as catalysts is costly.