List of top Chemistry Questions

The radius in the hydrogen atom in the ground state is $0.53$ \AA. The radius of $Li^{+2}$ ion (atomic number $= 3$) in a similar state is \ldots..

निम्नलिखित अभिक्रियाओं में कार्बनिक उत्पादों X और Y में उपस्थित क्लोरीन परमाणुओं की संख्याएँ क्रमशः हैं: 
 

Which of the following are fat soluble vitamins?
(A) Vitamin A
(B) Vitamin B
(C) Vitamin D
(D) Vitamin E
(E) Vitamin K
Choose the correct answer from the options given below:
Which of the following compounds will not undergo an Azo coupling reaction?
Which of the following solutions is isotonic with human blood?
When blood cells are placed in \(1%\) (w/v) NaCl aqueous solution, what will happen to the cells?
Which of the following complexes shows maximum number of unpaired electrons?
The SI unit of rate constant for a first order reaction is:
The major product formed in the following reaction is: \[ CH_3CH=CH_2 \xrightarrow{HBr,\ peroxide} \ ? \]
Among the following compounds, the correct order of acidic strength is: \[ \text{Phenol},\quad p\text{-Nitrophenol},\quad p\text{-Methoxyphenol} \]
Aniline is converted into benzene by the following sequence of reactions: \[ \text{Aniline} \xrightarrow[\text{0--5}^\circ C]{NaNO_2/HCl A \xrightarrow{H_3PO_2} B \] The compounds \(A\) and \(B\) respectively are:}
Which of the following solutions will conduct electricity most effectively?
The hybridization of carbon atom in \(CH_4\) molecule is:
The number of sigma \((\sigma)\) and pi \((\pi)\) bonds respectively in ethene molecule are:
The IUPAC name of the compound \[ CH_3-CH(CH_3)-CH_2-OH \] is:
For the reaction: \[ 2A \rightarrow Products \] the rate law is: \[ \text{Rate}=k[A]^2 \] If the concentration of \(A\) is doubled, the rate of reaction will become:
The violet colour of \(KMnO_4\) solution is due to:
The Nernst equation for a half-cell reaction at \(298\,K\) is:
The standard electrode potential of zinc electrode is \(-0.76\,V\) and that of copper electrode is \(+0.34\,V\). The standard EMF of the Daniell cell is:
For a first order reaction, the time required for completion of \(75\%\) of the reaction is \(40\) minutes. The half-life of the reaction is:
{The correct order of the rate of the reaction for the following reaction with respect to nucleophiles is:} \[ \mathrm{CH_3Br + Nu^- \rightarrow CH_3Nu + Br^-} \]

The correct statements are:

  • Activation energy for enzyme catalysed hydrolysis of sucrose is lower than that of acid catalysed hydrolysis.
  • During denaturation, secondary and tertiary structures of a protein are destroyed but primary structure remains intact.
  • Nucleotides are joined together by glycosidic linkage between \( C_1 \) and \( C_4 \) carbons of the pentose sugar.
  • Quaternary structure of proteins represents overall folding of the polypeptide chain.

Identify the correct statements.

  • Arginine and Tryptophan are essential amino acids.
  • Histidine does not contain heterocyclic ring in its structure.
  • Proline is a six membered cyclic ring amino acid.
  • Glycine does not have chiral centre.
  • Cysteine has characteristic feature of side chain as \( \mathrm{MeS-CH_2-CH_2-} \)
{Given below are two statements: Statement I: Among \[ [\mathrm{Cu(NH_3)_4}]^{2+}, [\mathrm{NiO_3}]^{2+}, [\mathrm{Ni(NH_3)_6}]^{2+} \text{ and } [\mathrm{Mn(H_2O)_6}]^{2+}, \] \( [\mathrm{Mn(H_2O)_6}]^{2+} \) has the maximum number of unpaired electrons. Statement II: The number of pairs among \[ [\mathrm{NiCl_4}]^{2-},\ [\mathrm{NiO_4}]^{2-} \] and \[ [\mathrm{NiO_4}],\ [\mathrm{O_4}]^{2-} \] that contain only diamagnetic species is two. In the light of the above statements, choose the correct answer from the options given below:}
\( \mathrm{MnO_4^{2-}} \) in acidic medium disproportionates to :