Solution:
Statement I: Boron is extremely hard indicating its high lattice energy.
Boron forms a giant covalent structure rather than an ionic lattice. Its hardness is due to its strong covalent network, not high lattice energy. Therefore, Statement I is incorrect.
Statement II: Boron has the highest melting and boiling point compared to its other group members.
Boron has a very high melting and boiling point due to its strong covalent network structure. This is true compared to the other group 13 elements. Therefore, Statement II is correct.
Therefore, Statement I is incorrect but Statement II is correct.
Correct Answer: (1) Statement I is incorrect but Statement II is correct
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 : \(A_2 \rightleftharpoons 2A\)