Which can adsorb a larger volume of hydrogen gas?

$3.12 \, g$ of oxygen is adsorbed on $1.2 \, g$ of platinum metal. The volume of oxygen adsorbed per gram of the adsorbent at $1 \, atm$ and $300 \, K$ in $L$ is ..... .
$[R = 0.0821 \, L \, atm \, K^{-1} \, mol^{-1}]$

Which of the following is $NOT$ a characteristic of chemisorption?

Choose the correct statement for chemical adsorption.

Assertion $(A)$: van der Waals' forces are responsible for chemisorption.
Reason $(R)$: High temperature is favourable for chemisorption.
The correct answer is

Give a reason why a finely divided substance is more effective as an adsorbent.