Which of the following gases is readily adsorbed by solid adsorbent?

$10 \ g$ of a gas is adsorbed on $500 \ g$ of solid at $10 \ bar$. If the pressure is increased to $20 \ bar$, $14 \ g$ of the gas is adsorbed by the same solid at the same temperature. What is the slope of Freundlich adsorption isotherm?

Find the temperature from the following graph at which the highest amount of a gas is adsorbed. (in $K$)

The correct statement regarding chemisorption is

According to the Langmuir adsorption isotherm,the amount of gas adsorbed at very high pressures:

Which of the following forces is responsible for physisorption?