Chemisorption results in a unimolecular layer.

The enthalpy change during physisorption is in the range of 100 to $140 \mathrm{~kJ} \mathrm{~mol}^{-1}$.

Chemisorption is an endothermic process.

Lowering the temperature favors physisorption processes.

the reaction of $\mathrm{Al}_{2} \mathrm{O}_{3}$ with coke $(\mathrm{C})$ at a temperature $>2500^{\circ} \mathrm{C}$.

the neutralization of aluminate solution by passing $\mathrm{CO}_{2}$ gas to precipitate hydrated alumina $\left(\mathrm{Al}_{2} \mathrm{O}_{3} \cdot 3 \mathrm{H}_{2} \mathrm{O}\right)$.

the dissolution of $\mathrm{Al}_{2} \mathrm{O}_{3}$ in hot aqueous $\mathrm{NaOH}$.

the electrolysis of $\mathrm{Al}_{2} \mathrm{O}_{3}$ mixed with $\mathrm{Na}_{3} \mathrm{AlF}_{6}$ to give $\mathrm{Al}$ and $\mathrm{CO}_{2}$.

paramagnetic

bent in geometry

an acidic oxide

colorless

$\mathbf{P}$ can be reduced to a primary alcohol using $\mathrm{NaBH}_{4}$.

Treating $\mathbf{P}$ with conc. $\mathrm{NH}_{4} \mathrm{OH}$ solution followed by acidification gives $\mathbf{Q}$.

Treating $\mathbf{Q}$ with a solution of $\mathrm{NaNO}_{2}$ in aq. $\mathrm{HCl}$ liberates $\mathrm{N}_{2}$.

$\mathbf{P}$ is more acidic than $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}$.