List of top Chemistry Questions asked in CBSE CLASS XII

In the Hinsberg method for separation of primary, secondary, and tertiary amines, the reagent used is:
Which of the following compounds would be hydrolyzed by aqueous KOH most easily?
Pyranose ring of glucose is formed due to the reaction between:
Assertion (A): Phenol is strongly acidic as compared to ethanol.
Reason (R): Phenoxide ion is more stable than ethoxide ion.
The gas evolved when methylamine reacts with HNO\textsubscript{2 is:}
Assertion (A): The boiling points of alkyl halides decrease in the order $R_1>R_3>R_2>R_4$.
Reason (R): The van der Waals forces of attraction decrease in the order $R_1>R_3>R_2>R_4$.
Hoffmann Bromamide degradation reaction is given by:
Which of the following aldehydes will undergo Cannizzaro reaction?

The elements of the 3d transition series are given as: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn. Answer the following:

Copper has an exceptionally positive \( E^\circ_{\text{M}^{2+}/\text{M}} \) value, why?

Out of Fe$^{3+}$, Sc$^{3+}$, Cr$^{3+}$ and Co$^{3+}$ ions, the one which is colourless in aqueous solution is:
Assertion (A): Cuprous salts are diamagnetic.
Reason (R): Cuprous ion has completely filled 3d-orbitals.

In the Haworth structure of the following carbohydrate, various carbon atoms have been numbered. The anomeric carbon is numbered as:

In the given reaction sequence, the structure of Y would be:

Out of the following statements, the incorrect statement is:
The value of Henry's constant K$_H$ is:
Assertion (A): n-Butyl chloride has higher boiling point than n-Butyl bromide.
Reason (R): C—Cl bond is more polar than C—Br bond.
The product of the oxidation of I$^-$ with MnO$_4^-$ in alkaline medium is:
During electrolysis of dilute H$_2$SO$_4$ using platinum electrodes, the gas evolved at the anode is:
The reaction $R$ -OH + Na $\longrightarrow$ RO$^-$ Na$^+$ + $\frac{1}{2}$ H$_2$ (g) suggests that alcohols are:
The activation energy (E$_a$) of a reaction can be determined from the slope of which of the following plots?
Assertion (A): Cooking time is reduced in pressure cooker.
Reason (R): Boiling point of water inside the pressure cooker is elevated.
Assertion (A): Actinoids show irregularities in their electronic configurations.
Reason (R): Actinoids are radioactive in nature.
Which of the following transition metal ion is not coloured?
The freezing point of one molal KCl solution, assuming KCl to be completely dissociated in water, is: (\(K_f\) for water = 1.86 K kg mol\(^{-1}\))
Which of the following is the softest metal?