When comparing bond dissociation energies:
• Consider bond length: shorter bonds generally have higher bond energy.
• Check for lone pair-lone pair repulsions, which can weaken bonds, as seen in F2.
Cl2
I2
F2
Br2
- Bond dissociation energy is the energy required to break a bond in a molecule. - The bond energy order for halogens is:
\(Cl_2 > Br_2 > F_2 > I_2.\)
- Although F2 has a shorter bond length than Cl2, the bond energy of F2 is lower due to lone pair-lone pair repulsions. - Cl2 has the highest bond dissociation energy as it has the optimal bond length and no significant repulsions.
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
The cycloalkene (X) on bromination consumes one mole of bromine per mole of (X) and gives the product (Y) in which C : Br ratio is \(3:1\). The percentage of bromine in the product (Y) is _________ % (Nearest integer).
Given:
\[ \text{H} = 1,\quad \text{C} = 12,\quad \text{O} = 16,\quad \text{Br} = 80 \]

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,