List of top Chemistry Questions on Organic Reactions asked in CBSE Class Twelve Board Exam

Chlorobenzene to biphenyl 

Identify P, Q and R in the following reaction sequence:
\[ P \xrightarrow{\text{NH}_3} \text{CH}_3\text{COO}^- \text{NH}_4^+ \xrightarrow{\Delta} Q \xrightarrow{\text{PCl}_5} R \]
Convert aniline to:
(I) benzene
(II) sulphanilic acid
Convert aniline to:
(I) p-bromoaniline
(II) phenol
The treatment of ethyl bromide with alcoholic silver nitrite gives:
CH3CH2OH can be converted to CH3CHO by :
Which reagents are required for one step conversion of Chlorobenzene to Diphenyl?
How can you obtain the following from aniline? Give only chemical equations.
Draw the structures of the major monohalo products in each of the following reactions:
structures of the major monohalo products

The acid formed when propyl magnesium bromide is treated with CO_2 followed by acid hydrolysis is:

The best reagent for converting propanamide into propanamine is:

Identify A and B in each of the following reaction sequence: 
(a) \[ CH_3CH_2Cl \xrightarrow{NaCN} A \xrightarrow{H_2/Ni} B \] 

(b) \[ C_6H_5NH_2 \xrightarrow{NaNO_2/HCl} A \xrightarrow{C_6H_5NH_2} B \] 

Write the product obtained when D-glucose reacts with \( H_2N - OH \).

What will be formed after oxidation of secondary alcohol with chromic anhydride (CrO3)?
How do you convert:
Chlorobenzene to biphenyl

A certain reaction is 50 complete in 20 minutes at 300 K and the same reaction is 50 complete in 5 minutes at 350 K. Calculate the activation energy if it is a first order reaction. Given: \[ R = 8.314 \, \text{J K}^{-1} \, \text{mol}^{-1}, \quad \log 4 = 0.602 \] 

Aromatic primary amines cannot be prepared by Gabriel Phthalimide synthesis. 

Write the chemical equations when:
(a) Ethanal is treated with 2,4-dinitrophenylhydrazine?
(b) Propanone is treated with Zn(Hg) and conc. HCl?
Which of the following is most reactive towards nucleophilic substitution reaction?
(B) (a) Write chemical equations of the following reactions: (i) Phenol is treated with conc. \( HNO_3 \).
(ii) Propene is treated with \( B_2H_6 \) followed by oxidation by \( H_2O_2 / OH^- \).
(iii) Sodium t-butoxide is treated with \( CH_3Cl \).
(B) (a) Write chemical equations of the following reactions: (i) Phenol is treated with conc. \( HNO_3 \).
(ii) Propene is treated with \( B_2H_6 \) followed by oxidation by \( H_2O_2 / OH^- \).
(iii) Sodium t-butoxide is treated with \( CH_3Cl \).
(A) An organic compound \( A \), molecular formula \( C_2H_6O \), oxidises with \( Cr_2O_7 \) to form a compound \( B \). Compound \( B \) on warming with iodine and aqueous solution of NaOH gives a yellow precipitate of compound \( C \). When compound \( A \) is heated with conc. \( H_2SO_4 \) at 413 K, it gives a compound \( D \), which on reaction with excess HI gives compound \( E \). Identify compounds \( A \), \( B \), \( C \), \( D \), and \( E \) and write chemical equations involved.
(B) Complete each synthesis by giving missing starting material, reagent, or products:
\includegraphics[width=0.5\linewidth]{ch32i.png}
(c) How will you convert the following:
(i) Toluene to benzoic acid.
(ii) Ethanol to propan-2-ol.
(iii) Propanal to 2-hydroxy propanoic acid.
(A) An organic compound \( A \), molecular formula \( C_2H_6O \), oxidises with \( Cr_2O_7 \) to form a compound \( B \). Compound \( B \) on warming with iodine and aqueous solution of NaOH gives a yellow precipitate of compound \( C \). When compound \( A \) is heated with conc. \( H_2SO_4 \) at 413 K, it gives a compound \( D \), which on reaction with excess HI gives compound \( E \). Identify compounds \( A \), \( B \), \( C \), \( D \), and \( E \) and write chemical equations involved.