List of top Questions asked in CBSE CLASS XII

The following initial rate data were obtained for the reaction: \[ 2\text{NO (g)} + \text{Br}_2 \text{(g)} \rightarrow 2 \text{NOBr (g)} \] initial rate data
Which isomer of C4H9Cl has the lowest boiling point?
Out of chlorobenzene and 2,4,6-trinitrochlorobenzene, which is more reactive towards nucleophilic substitution and why?
Identify the type of isomerism exhibited by the following complexes:
(i) [Co(NH3)5NO2]2+
(ii) [Co(en)3]3+Cl3
Arrange the following complexes in the increasing order of conductivity of their solution: \[ [\text{Cr(NH}_3\text{)}_5\text{Cl}] \text{Cl}_2, \, [\text{Cr(NH}_3\text{)}_3\text{Cl}_3], \, [\text{Cr(NH}_3\text{)}_6\text{Cl}_3] \]
Write the formula for the following coordination compound: Potassium tetrahydroxidozincate (II)
Write the main product in each of the following reactions: 
oxidation of the hydroboration product
Write the mechanism of the following reaction: \[ \text{CH}_3\text{CH}_2\text{OH} \xrightarrow{H^+ \, 443\, \text{K}} \text{CH}_2 = \text{CH}_2 \]
What is peptide linkage?
Write two differences between order of reaction and molecularity of reaction.
Write the chemical equations when: Pentan-3-one is treated with H$_2$N–NH$_2$ followed by heating with KOH in high boiling solvent such as ethylene glycol.
Draw the structures of major monohalo products in each of the following reactions:
monohalo products
Assertion (A): Transition metals have high enthalpy of atomization. Reason (R): This is because transition metals have low melting points.
Assertion (A): The pK$_a$ of O$_2$N–CH$_2$–COOH is lower than that of CH$_3$–COOH. Reason (R): The –NO$_2$ group shows an electron-withdrawing effect, which increases the acidic character of O$_2$N–CH$_2$–COOH.
The IUPAC name of CH$_3$–C(=O)–CH$_2$–C(=O)–H is:
Decarboxylation of sodium benzoate on heating with soda lime gives:
The product formed as a result of reaction of CH$_3$MgBr and CO$_2$ followed by hydrolysis is:
The most stable oxidation state of Iron is:
The Valence Bond Theory (VBT) explains the formation, magnetic behaviour and geometrical shapes of coordination compounds whereas ’The Crystal Field Theory’ for coordination compounds is based on the effect of different crystal fields (provided by ligands taken as point charges), on the degeneracy of d-orbital energies of the central metal atom/ion. The splitting of the d-orbitals provides different electronic arrangements in strong and weak crystal fields. The crystal field theory attributes the colour of the coordination compounds to d-d transition of the electron. Coordination compounds find extensive applications in metallurgical processes, analytical and medicinal chemistry.
Answer the following questions:
Write the anode, cathode, and overall reaction of lead storage battery.
State Faraday's first law of electrolysis. How much charge in Faraday is required for the reduction of 1 mol of MnO\(_4^-\) to Mn\(^{2+}\)?
The resistance of 0.05 M CH\(_3\)COOH solution is found to be 100 ohm. If the cell constant is 0.0354 cm\(^{-1}\), calculate the molar conductivity of the acetic acid solution.
Write the main product in the following reaction:
ester to a primary alcohol
Give a simple chemical test to distinguish between benzaldehyde and ethanal.
How can you convert phenyl magnesium bromide to benzoic acid?