"Assertion: SO2 is enclosed in presence of powdered charcoal in a closed vessel, it is observed that the pressure of the gas increases Reasoning: The gas molecules concentrate at the surface of the charcoal."

"both assertion and reason are true and the reason is the correct explanation of the assertion. " "both assertion and reason are true but reason is not the correct explanation of the assertion. " "assertion is true but reason is false. " assertion is false but reason is true.

assertion is false but reason is true.

Due to adsorption at surface, the pressure of the gas decreases.