List of top Questions asked in UP Board XII- 2026

For which of the following ions will the magnetic moment ($\mu$) be maximum?

A proton, an electron and an \(\alpha\)-particle placed in a uniform electric field experience forces \(F_1\), \(F_2\) and \(F_3\) respectively. Then:

The unit of rate and rate constant is same for which order of reaction?

Define Molal depression constant. 48 g of ethylene glycol (C₂H₆O₂) is dissolved in 600 g of water. Calculate (i) depression in freezing point and (ii) freezing point of the solution. [Given K_f(water) = 1.86 °C kg mol^-1]
OR
Define molality and explain mole fraction. Calculate the mole fraction of solute and solvent of a 20% aqueous C₂H₆O₂ solution.

Explain by giving four examples that the alkoxy group (-OR) activates the aromatic ring towards electrophilic substitution.
OR
Describe two methods of preparation of phenol. Give two reactions that demonstrate the acidic nature of phenol. Compare the acidity of phenol with that of ethanol.

Write chemical equations of three methods of preparation and two chemical properties of benzaldehyde.
OR
Write short notes on the following: (i) Aldol condensation (ii) Cross aldol condensation (iii) Cannizzaro reaction (iv) Hell-Volhard-Zelinsky reaction (v) Kolbe electrolysis.

Describe the method of identification of primary, secondary and tertiary amines. Classify the following compounds into primary, secondary and tertiary amines: (i) C₆H₅NHCH₃ (ii) CH₃(CH₂)₂NH₂ (iii) (CH₃CH₂)₂NCH₃.

Explain the ring structure of glucose. What happens when D-glucose reacts with the following reagents? (i) Bromine water (ii) Hydroxylamine.

Describe two methods of preparation of alkyl halides. Also give equations. Explain the following reactions of alkyl halides with examples: (i) Nucleophilic substitution reaction (ii) Elimination reaction.
OR
Write chemical equations of chlorination, nitration, sulphonation, Friedel-Crafts reaction and Wurtz (Fittig) reaction of chlorobenzene.

(i) Explain the nature of the C-X bond. Give an example of a compound having sp³ C-X bonding. (ii) Write chemical equations of the following: (a) Carbylamine reaction (b) Hinsberg reaction.

(i) Write the IUPAC name of the following coordination compounds: (a) K₃[Cr(C₂O₄)₃] (b) [Co(NH₃)₅(CO₃)]Cl. (ii) Write the electronic configuration of the following: (a) Cr³⁺ (b) Cu.

Explain the structure of Nucleic Acid.

Explain with reasons:
(i) Transition metals show variable valency (variable oxidation states).
(ii) Copper is considered a transition metal even though it has a completely filled d-orbital \((3d^{10})\) in its \(+1\) state.

Discuss the factors that affect the velocity (rate) of a chemical reaction.

Explain the type of isomerism shown by the following complexes and give the structure of the isomers:
(i) \([\text{Co(NH}_3)_5(\text{NO}_2)](\text{NO}_3)_2\)
(ii) \([\text{Cr(NH}_3)_6][\text{Co(CN)}_6]\)
(iii) \([\text{Fe(NH}_3)_2(\text{CN})_4]^-\)

Explain electrode potential and standard electrode potential. The following reaction takes place in a cell: \[ \text{Zn(s)} + \text{Co}^{2+} \rightleftharpoons \text{Co(s)} + \text{Zn}^{2+} \] Calculate the standard cell potential \(E^\circ_{cell}\) of the cell. Given: \(E^\circ_{(\text{Zn} \rightarrow \text{Zn}^{2+})} = 0.76\,\text{V}\) and \(E^\circ_{(\text{Co} \rightarrow \text{Co}^{2+})} = 0.28\,\text{V}\) (oxidation potentials).

0.32 g of a new compound was dissolved in 25 g of water. The freezing point of this solution was found to be \(-0.201\,^\circ\text{C}\). Determine the molecular weight of this new compound. For water \(K_f = 1.86\,^\circ\text{C}\;\text{kg mol}^{-1}\).

The velocity constant \(K\) for a first order reaction was found to be \(5.5 \times 10^{-14}\,s^{-1}\). Calculate the half life of this reaction.

Draw a diagram to show the splitting of d-orbitals in an octahedral crystal field.

What is Lanthanide contraction? What are the consequences of Lanthanide contraction?

Write chemical equations of the Etard reaction and the Gattermann-Koch reaction.

Is the following reaction possible or not? Explain with reasons. \[Zn(NO_3)_2 + 2Ag \rightarrow 2AgNO_3 + Zn\]

How will you obtain the following from phenol? (i) Picric acid (ii) Benzoquinone.

In which cell does the following reaction take place? \[2H_2(g) + O_2(g) \rightarrow 2H_2O(l)\]

The velocity (rate) constant of a second order reaction is generally expressed as: