List of practice Questions

How will you obtain the following from aniline ? Write the chemical equations involved :
(a) Sulphanilic acid
(b) 2,4,6-Tribromoaniline
(c) Acetanilide

An organic compound (A) with molecular formula $\mathrm{C_3H_5N}$ on reaction with $\mathrm{C_6H_5MgBr}$ followed by hydrolysis, gives a compound (B). Compound (B) forms an orange-red precipitate with 2,4-DNP reagent and does not give iodoform test. It neither reduces Tollens' or Fehling's reagent nor does it decolourise bromine water. On drastic oxidation with chromic acid it gives a carboxylic acid (C) having molecular formula $\mathrm{C_7H_6O_2}$. Identify the compounds (A), (B) and (C). Write the reactions of compound (A) with $\mathrm{C_6H_5MgBr}$ followed by hydrolysis to give compound (B).

How do you explain the following ?
(a) Presence of an aldehyde group in glucose
(b) Presence of a primary alcoholic group in glucose

Explain why, on addition of 1 mol of KCl to 1 litre of water, the boiling point of water increases, while the addition of 1 mol of methyl alcohol to 1 litre of water decreases the boiling point.

State Kohlrausch's law of independent migration of ions. With the help of a curve, explain why it is not easy to determine $\mathrm{\Lambda^\circ_m}$ for weak electrolytes by extrapolating the concentration – molar conductivity curve, as it is for strong electrolytes.

An antifreeze solution is prepared by dissolving 31 g of ethylene glycol (Molar mass = 62 g $\mathrm{mol^{-1}}$) in 600 g of water. Calculate the freezing point of the solution. ($\mathrm{K_f}$ for water = 1·86 K kg $\mathrm{mol^{-1}}$)

Answer the following questions about the complexes $\mathrm{[NiCl_4]^{2-}}$ and $\mathrm{[Ni(CN)_4]^{2-}}$ :
(i) Write the hybridization involved in each case.
(ii) Which of them is the inner orbital complex and which one is the outer orbital complex ?
(iii) Compare their magnetic behaviour. [Atomic number : Ni = 28]

For a reaction A + B → Products, the rate law is $\mathrm{Rate = k[A][B]^{3/2}}$. Write the overall order of the reaction. Can this reaction be an elementary reaction ? Give reason in support of your answer.

For the compound having molecular formula $\mathrm{C_4H_9Br}$, write :
(a) the isomer which is most reactive towards $\mathrm{S_N1}$ displacement.
(b) the isomer which, on reacting with Na metal in the presence of dry ether, gives 2,5-Dimethylhexane.

Write IUPAC names of the following compounds :
(i) $\mathrm{[PtCl_2(en)_2]SO_4}$
(ii) $\mathrm{(NH_4)_2[CoF_4]}$

Define the following terms with a suitable example in each case :
(i) Ambidentate ligand
(ii) Double salt

Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.

Assertion (A): Monobromination of aniline can be conveniently done by protecting the amino group by acetylation.
Reason (R): Acetylation increases the activation effect of the amino group.

Assertion (A): Order of reaction is applicable to elementary as well as complex reactions.
Reason (R): For a complex reaction, molecularity has no meaning.

Consider the following compounds : Chlorobenzene (I), 2,4,6-trinitrochlorobenzene (II), 2,4-dinitrochlorobenzene (III), 4-nitrochlorobenzene (IV).
The correct order of increasing rate of nucleophilic substitution reactions of these compounds is :

The half-life periods of decomposition of $\mathrm{NH_3}$ for different initial pressures are given below :

The order of the reaction is :

1 mole of liquid A and 2 moles of liquid B make a solution having a total vapour pressure 40 torr. The vapour pressure of pure A and pure B are 30 torr and 45 torr respectively. The above solution :

Assertion (A): Ethers have lower boiling points than the boiling points of alcohols.
Reason (R): This is due to the presence of hydrogen bonding in alcohols.

The mole fraction of a solute in 2·0 molal aqueous solution is :

Which of the following transition metals shows +1 and +2 oxidation states ?

On hydrolysis, which of the following carbohydrates gives only $\mathrm{\beta}$-glucose ?

Which of the following product is formed when salicylic acid is treated with $\mathrm{(CH_3CO)_2O}$ in the presence of acid ?

Which reagent is used to distinguish between primary, secondary and tertiary amines ?

On electrolysis of very dilute aqueous solution of NaCl using platinum electrodes :

The correct order of decreasing basic strength in aqueous solution of the following is :