List of top Questions asked in CBSE CLASS XII- 2025

How do you convert:
Chlorobenzene to biphenyl

Draw the structure of the major monohalo product for each of the following reactions:

Draw the structure of the major monohalo product for each of the following reactions:

Using \( E^\circ \) values of X and Y given below, predict which is better for coating the surface of iron to prevent corrosion and why?
Given: \( E^\circ_{X^{2+}/X} = -2.36 \, \text{V} \) \( E^\circ_{Y^{2+}/Y} = -0.14 \, \text{V} \) \( E^\circ_{Fe^{2+}/Fe} = -0.44 \, \text{V} \)

State the following:
Faraday’s first law of electrolysis

State the following:
Kohlrausch law of independent migration of ions

Phenols undergo electrophilic substitution reactions readily due to the strong activating effect of the OH group attached to the benzene ring. Since the OH group increases the electron density more to the ortho- and para- positions, one of the examples of the aldehyde group being introduced on the aromatic ring of phenol, ortho to the hydroxyl group. This is a general method used for the ortho-formylation of phenols.
Answer the following questions:

Read the passage carefully and answer the questions that follow.
Passage: The rate of a chemical reaction is expressed either in terms of decrease in the concentration of reactants or increase in the concentration of a product per unit time. Rate of the reaction depends upon the nature of reactants, concentration of reactants, temperature, presence of catalyst, surface area of the reactants and presence of light. Rate of reaction is directly related to the concentration of reactant. Rate law states that the rate of reaction depends upon the concentration terms on which the rate of reaction actually depends, as observed experimentally. The sum of powers of the concentration of the reactants in the Rate law expression is called order of reaction while the number of reacting species taking part in an elementary reaction which must collide simultaneously in order to bring about a chemical reaction is called molecularity of the reaction.
 Answer the following questions:

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

Given below are types of fractures in List - I with their features in List - II: 

Match the items of List- I with List- II and choose the correct option from the following:

Given below are two statements, one of which is labelled as Assertion (A) and the other is labelled as Reason (R). Read both the statements carefully: Assertion (A): The risk of cancer can be reduced by eating more colorful vegetables, fruits, and other plant-foods that have certain phytochemicals in them. Reason (R): Non-nutritive components of the diet are part of a balanced diet. In the context of the above two statements, which one of the following is correct?