List of top Chemistry Questions

Write chemical equations for the following reactions:
(a) Hydroboration – Oxidation reaction:
(b) Williamson Synthesis:
(c) Friedel-Crafts Alkylation of Anisole:
(d) Reimer-Tiemann Reaction:
Which of the following compounds will give a ketone on oxidation with chromic anhydride (CrO3})?
In acidic medium, which of the following does not change its colour?
Calculate the potential of Iron electrode in which the concentration of Fe2+ ion is 0.01 M. Given \( E^{\circ}_{\text{Fe}^{2+}/\text{Fe}} = -0.45 \, \text{V at 298 K} \)
[Given: log 10 = 1]
What type of deviation is shown by ethanol and acetone mixture ? Give reason. What type of azeotropic mixture is formed by that deviation ?
Which one of the following first row transition elements is expected to have the highest third ionization enthalpy?
The vapour pressure of a solvent at 283 K is 100 mm Hg. Calculate the vapour pressure of a dilute solution containing 1 mole of a strong electrolyte AB in 50 moles of the solvent at 283 K (assuming complete dissociation of solute AB).
What is the structural feature that characterizes a reducing sugar?
How many Faradays are required for the oxidation of one mole of \( \text{H}_2\text{O} \) to \( \text{O}_2 \)?
Write the chemical equation when:
(a) Butan-2-one is treated with Zn(Hg) and conc. HCl.
(b) Two molecules of benzaldehyde are treated with conc. NaOH.
At the same temperature, \( CO_2 \) gas is more soluble in water than \( O_2 \) gas. Which one of them will have a higher value of \( K_H \) and why?
$\Delta_{vap}H^\circ$ for water is $+40.49 \, \text{kJ mol}^{-1}$ at 1 bar and $100^\circ\text{C}$. Change in internal energy for this vaporisation under same condition is .............. kJ mol$^{-1}$. (Integer answer)
(Given R = 8.3 J K$^{-1}$ mol$^{-1}$)
Which of the following alkyl halides will undergo S$_N$1 reaction most readily?
Anisole reacts with HI to give:
Write the stepwise mechanism of nucleophilic addition reactions in the carbonyl compounds.
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 were obtained for the reaction
A 1% solution of solute ‘X’ is isotonic with a 6% solution of sucrose (molar mass = \( 342 \) g mol\(^{-1}\)). The molar mass of solute ‘X’ is:
An azeotropic solution of two liquids has a boiling point lower than either of them when it:
The relative lowering of vapor pressure of an aqueous solution containing a non-volatile solute is 0.0225. The mole fraction of the non-volatile solute is:
Phenol dimerises in benzene having van’t Hoff factor 0.54. Its degree of association is:
Assertion (A): When NaCl is added to water, elevation in boiling point is observed. Reason (R): Elevation in boiling point is a colligative property.
Phenol does not undergo nucleophilic substitution reaction easily due to:
Assertion (A): p-Nitroaniline is a weaker base than p-toluidine. Reason (R): The electron-withdrawing effect of \(-NO_2\) group in p-nitroaniline makes it a weaker base.
Assertion (A): Diazonium salts of aromatic amines are more stable than those of aliphatic amines. Reason (R): Diazonium salts of aliphatic amines show resonance.
Assertion (A): Aliphatic primary amines can be prepared by Gabriel phthalimide synthesis. Reason (R): Alkyl halides undergo nucleophilic substitution with anion formed by phthalimide.