List of top Chemistry Questions

Consider the following (unbalanced) reactions:

\[ \text{BF}_3 + \text{NaH} \xrightarrow{450\,\mathrm{K}} X + \text{NaF} \]

\[ X + \text{H}_2\text{O} \rightarrow Y + \text{H}_2 \uparrow \]

The correct statements about \(X\) and \(Y\) are:

  1. \(X\) is an electron-deficient molecule
  2. In \(X\), a B--B bond is present
  3. \(Y\) is a weak tribasic acid
  4. \(Y\) acts as a Lewis acid
Identify the set of molecules which are not in the correct order of their dipole moments.

Match the following molecules with their respective molecular shapes:

 The functional groups present in the product ‘X’ of the reaction given below are:

The dihedral angles in gaseous and solid phases of H\(_2\)O\(_2\) molecule respectively are
Which of the following does not exist?

The set of elements which obey the general electronic configuration \( (n-1)d^{10} ns^2 \) is:}

The major components of cement are:

Match the following: 

Which of the following will have a spin-only magnetic moment of 2.86 BM?
Acrolein (X) is one of the chemicals formed when \( O_3 \) and \( NO_2 \) react with unburnt hydrocarbons present in polluted air. The structure of 'X' is:
In the given sequence of reactions: \[ \text{P}_4 + \text{NaOH} + \text{H}_2\text{O} \;\longrightarrow\; \dots \;\longrightarrow\; X \;+\; 2\,\text{NaH}_2\text{PO}_2 \;\longrightarrow\; \dots \] The final product obtained with copper and \(\text{H}_2\text{SO}_4\) is:
In which of the following, ions are correctly arranged in the increasing order of oxidizing power?
At 61 K, one mole of an ideal gas of 1.0 L volume expands isothermally and reversibly to a final volume of 10.0 L. What is the work done in the expansion?

The correct IUPAC name of the given compound is:

The incorrect rule regarding the determination of significant figures is:
Which of the following is an example of allylic halide?
At T(K), \( K_c \) for the dissociation of \( PCl_5 \) is \( 2 \times 10^{-2} \) mol L\(^{-1}\). The number of moles of \( PCl_5 \) that must be taken in 1.0 L flask at the same temperature to get 0.2 mol of chlorine at equilibrium is
Cellulose is a polysaccharide and is made of:

Match the following elements with their respective blocks in the periodic table:
 

The pair of molecules/ions with same geometry but central atoms in different states of hybridization is:
Identify the pair in which the difference in bond order value is maximum.
In the reaction: \[ \text{Pt} + 3:1 \,\text{mixture of} \,(\text{conc. HCl} + \text{conc. HNO}_3) \rightarrow [\text{X}]^{2-}, \] What is the oxidation state of Pt in the complex ion \([X]^{2-}\)?
The monomer which is present in both Bakelite and Melamine polymers is:

Compound ‘A’ on heating with soda lime gives propane. Identify the compound 'A'.