List of top Questions asked in CBSE CLASS XII- 2026

Predict the alkene formed by dehydrohalogenation of 1-Bromo-1-methylcyclohexane.
Though chlorine shows strong $-I$ effect, why is it ortho/para directing?
Why are magnesium blocks attached to iron water pipelines?
61 g benzoic acid (M = 122 g mol$^{-1}$) dissolved in 500 g benzene. Vapour pressure of pure benzene = 66 torr. Assume complete dimerisation. Calculate vapour pressure of solution.
For decomposition of $H_2O_2$ by $I^-$: Step I: $H_2O_2 + I^- \rightarrow H_2O + IO^-$ (slow). Step II: $H_2O_2 + IO^- \rightarrow H_2O + I^- + O_2$ (fast). (a) Write rate law. (b) Determine order w.r.t. $H_2O_2$ and $I^-$ and overall order. (c) Molecularity of Step II.
Under what condition can a bimolecular reaction become kinetically first order?
Give structures of A, B and C: $CH_3Cl \xrightarrow{KCN}$ A $\xrightarrow{LiAlH_4}$ B $\xrightarrow{CHCl_3 + \text{alc. } KOH, \Delta}$ C
Why are products of electrolysis of $AgNO_3$ different with silver electrodes and platinum electrodes?
Draw the structures of major products: (a) Chlorobenzene + $CH_3Cl$ / Na, dry ether
(b) p-Hydroxyphenethyl alcohol + HBr
What happens when: (a) Propanenitrile is treated with phenyl magnesium bromide followed by hydrolysis? (b) p-Fluorotoluene is treated with $CrO_3$ in presence of acetic anhydride followed by hydrolysis with aqueous acid? (c) Phthalic acid is treated with $NH_3$ followed by heating?
When $CoCl_3 \cdot 6NH_3$ is mixed with excess $AgNO_3$ solution, 3 moles of $AgCl$ are precipitated per mole. Write its structural formula, IUPAC name, hybridisation and magnetic behaviour (VBT).
Why is DC not used for measuring resistance of ionic solution?
Name the sugar present in sugarcane. What are the hydrolysis products of this sugar? Is this sugar a reducing sugar?
Assertion (A): $E^\circ_{Cu^{2+}/Cu} = +0.34$ V.
Reason (R): It is due to low $\Delta H^\circ_{hyd}$ and high $\Delta H^\circ_a$.
Reactions of which order show rate independent of concentration of reactant? Give one example.
Explain with the help of Henry's law: (i) Bends (ii) Anoxia
How does sprinkling of salt help in clearing snow-covered roads in hilly areas? Name the colligative property involved.
Write the formulas of: (a) Mercury(I) tetrathiocyanato-S-cobaltate(III)
(b) Dichloridobis(ethane-1,2-diamine)platinum(IV) nitrate
Which reagent is used to convert benzene diazonium chloride to benzene?
Assertion (A): Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
Reason (R): Diazonium salts of aromatic amines undergo resonance.
Which of the following is a water-soluble vitamin?
Assertion (A): For complex reactions, order of reaction is given by the fast step.
Reason (R): Order of reaction is determined experimentally.
Consider the cell at 298 K: $Mg(s)|Mg^{2+}(1.0M)||Cu^{2+}(1.0M)|Cu(s)$. How can we increase the emf of the cell using the same substances?
Assertion (A): Alcohols act as Bronsted bases as well as Bronsted acids.
Reason (R): Alcohols react as both nucleophiles and electrophiles.
Number of possible stereoisomers for the complex $[Co(en)_2Cl_2]Cl$ will be: