List of top Chemistry Questions

Aspirin is obtained by acetylation of

Which of the following represents the fraction of molecules with energies equal to or greater than \(E_a\)?

What will happen during the electrolysis of aqueous solution of \(CuCl_2\) by using platinum electrodes?

Which of the following is not a transition metal?

Which of the following solutions will have the lowest freezing point in water?

Which of the following curve represents the first order reaction?

Identify the paramagnetic outer orbital complex ion from the following.

The total number of geometrical and optical isomers possible with \([CoCl_2(en)_2]Cl\) are respectively

Consider the following statements and select the correct option: Statement-I : \(CH_3^-\) lacks hyperconjugative stability. Statement-II : There is no vacant \(p\)-orbital in \(CH_3^-\) and as such it cannot participate in hyperconjugation.

The IUPAC name of the following compound is \[ CH_3-C\equiv C-CH=CH-CH=CH-CH_3 \]

A first-order reaction is carried out at two different temperatures of \(300\,K\) and \(310\,K\), where the rate constants are \(k_1\) and \(k_2\) respectively. The activation energies of the reaction in absence and presence of catalyst are \(E_{a1}\) and \(E_{a2}\) respectively. Which of the following options is correct?

In which of the following compounds, an electrophile prefers to attack the meta position?

Which of the following lacks aromatic properties?

Identify the incorrect reaction from the following.

Select the option in which all the given functional groups exhibit \(+R\) effect.

Identify the two ions having the highest and lowest length of ionic radius respectively out of the following: \[ F^{-},\quad Mg^{2+},\quad Na^{+},\quad O^{2-} \]

The increasing order of \(2s\)-orbital's of the following atoms with respect to energy is \[ H,\; K,\; Li,\; Na \]

If \(\lambda_{Li^{2+}}\) and \(\lambda_D\) represent the wavelengths related to first line (shortest line) of Lyman series of line spectrum of \(Li^{2+}\) and \(^2_1H\) respectively, then \(\lambda_{Li^{2+}} : \lambda_D\) is

An acid of general molecular formula HA is \(25\%\) dissociated during the study of boiling point of its solution. If the calculated elevation of boiling point of the solution is \(1.62\,K\), find the observed value of elevation of boiling point of the solution.

\(45\,g\) urea \((CO(NH_2)_2)\) dissolved in \(1000\,g\) of water depresses the freezing point by \(1.395\,K\). The depression in freezing point of a solution of \(90\,g\) glucose \((C_6H_{12}O_6)\) in \(2000\,g\) water will be

Select the set of incorrect statements: Statement-I : The pH of neutral water at \(310\,K\) is lower than 7. Statement-II : The pH of an aqueous solution of \(1\times10^{-8}\,M\) HCl is 8. Statement-III : The ionization of \(CH_3COONa\) is suppressed in presence of \(CH_3COOH\). Statement-IV : CuS is precipitated when \(H_2S\) is passed through a solution of \(Cu^{2+}\) and \(Zn^{2+}\) ions in presence of dilute HCl since \(K_{sp}(CuS)\lt K_{sp}(ZnS)\).

Match the following reactions in Column-II with the names in Column-I. \[ \begin{array}{llll} (a) & \text{Cannizzaro reaction} & (p) & ArN_2^+Cl^- \xrightarrow{Cu/HBr} ArBr \\[10pt] (b) & \text{Carbylamine reaction} & (q) & C_6H_5CHO \xrightarrow{\text{Conc. NaOH}} C_6H_5CH_2OH + C_6H_5COONa \\[10pt] (c) & \text{Gattermann reaction} & (r) & ArN_2^+Cl^- \xrightarrow{CuCN/KCN} ArCN \\[10pt] (d) & \text{Sandmeyer reaction} & (s) & C_6H_5NH_2 \xrightarrow[alc.\,KOH]{CHCl_3,\ \Delta} C_6H_5NC \end{array} \]

State True (T) or False (F) and select the correct option:

• [(a)] Alcohols can react both as electrophile and nucleophile.

• [(b)] Ethanol is stronger than methanol with respect to acidic character.

• [(c)] The C--O bond length in phenol is slightly less than that in methanol.

• [(d)] The \(\angle C-O-C\) bond angle in methoxyethane is slightly smaller than normal tetrahedral angle.

A compound \(P\) on treatment with \(C_2H_5MgBr\) in presence of ether followed by acidic hydrolysis produces a compound \(Q\). \(Q\) on treatment with \(Cl_2/red\;P\) in mild condition produces a compound \(R\). Compound \(Q\) on heating with soda lime produces a hydrocarbon \(S\). Compounds \(P\), \(Q\), \(R\) and \(S\) are respectively

Match the metals/ions/compounds given in Column-I with the reactions where they act as catalyst as given in Column-II. \[ \begin{array}{llll} (a) & V_2O_5 & (p) & \text{Synthesis of ammonia by Haber's process} \\[6pt] (b) & \text{Fe powder} & (q) & \text{Hydrogenation of alkene} \\[6pt] (c) & Fe^{3+} & (r) & \text{Manufacture of } H_2SO_4 \text{ by Contact Process} \\[6pt] (d) & \text{Ni(s)} & (s) & \text{Oxidation of } I^- \text{ by } S_2O_8^{2-} \end{array} \]