List of top Chemistry Questions asked in CBSE CLASS XII

The best reagent for converting propanamide into propanamine is:

Which of the following statements is not true about glucose?

The acid formed when propyl magnesium bromide is treated with CO$_2$ followed by acid hydrolysis is:

Alkyl halides undergoing nucleophilic bimolecular substitution reaction involve:

Arrange the following compounds in increasing order of their boiling points:

In case of association, abnormal molar mass of solute will:

Acidified KMnO$_4$ oxidizes sulphite to:

Which of the following compounds will give a ketone on oxidation with chromic anhydride (CrO3})?

Draw the structures of major monohalo products in each of the following reactions: 


(b) Give reasons for the following:
(i) Grignard reagent should be prepared under anhydrous conditions.
(ii) Alkyl halides give alcohol with aqueous KOH whereas in the presence of alcoholic KOH, alkenes are formed

The product (X) obtained in the following reaction is:

Assertion (A): \( p \)-nitroaniline is a weaker base than \( p \)-toluidine.
Reason (R): The electron-donating \( -NO_2 \) group in \( p \)-nitroaniline makes it a weaker base.

Assertion (A): \( \Delta_{\text{mix}} H \) for an ideal solution is not equal to zero.
Reason (R): A–B interactions in an ideal solution are the same as between A–A and B–B interactions.

Write the chemical equations when:
(a) Ethanal is treated with 2,4-dinitrophenylhydrazine?
(b) Propanone is treated with Zn(Hg) and conc. HCl?

For a chemical reaction \( R \to P \), the variation in the concentration \([R]\) vs time \( t \) plot is given as:

(a) Predict the order of the reaction and write the unit of rate constant (\( k \)) for this order of reaction.
(b) What is the slope of the curve?

The suitable Grignard reagent used for the synthesis of

with methanal is:

Assertion (A): Fluoroacetic acid is a stronger acid than chloroacetic acid. Reason (R): This is due to greater electron-withdrawing nature of \( F \) than \( Cl \).