For \( \text{NO}_3^- \):
The structure of \( \text{NO}_3^- \) (nitrate ion) shows that nitrogen is involved in three sigma bonds and has no lone pairs on it.
The hybridization of nitrogen in \( \text{NO}_3^- \) is \( sp^2 \).
For \( \text{BCl}_3 \):
Boron in \( \text{BCl}_3 \) forms three sigma bonds with no lone pairs, resulting in a planar triangular structure.
The hybridization of boron in \( \text{BCl}_3 \) is \( sp^2 \).
For \( \text{ClO}_2^- \):
In \( \text{ClO}_2^- \) (chlorite ion), chlorine has two sigma bonds with oxygen atoms and two lone pairs of electrons.
The hybridization of chlorine in \( \text{ClO}_2^- \) is \( sp^3 \), resulting in a bent or V-shaped geometry.
For \( \text{ClO}_3^- \):
In \( \text{ClO}_3^- \) (chlorate ion), chlorine forms three sigma bonds with oxygen atoms and has one lone pair of electrons.
The hybridization of chlorine in \( \text{ClO}_3^- \) is \( sp^3 \), resulting in a pyramidal structure.
From the analysis above, \( \text{ClO}_2^- \) and \( \text{ClO}_3^- \) have \( sp^3 \) hybridization for the central atom.
The number of molecules/ions in which the central atom is involved in \( sp^3 \) hybridization is 2, corresponding to Option (1).
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,