Adding soap to water ................

The quenching of fluorescence depends on:

Sodium thiosulphate is used in photography to :-

The correct statement$(s)$ about surface properties is(are):
$[A]$ Adsorption is accompanied by decrease in enthalpy and decrease in entropy of the system.
$[B]$ The critical temperatures of ethane and nitrogen are $563 \ K$ and $126 \ K$,respectively. The adsorption of ethane will be more than that of nitrogen on the same amount of activated charcoal at a given temperature.
$[C]$ Cloud is an emulsion type of colloid in which liquid is dispersed phase and gas is dispersion medium.
$[D]$ Brownian motion of colloidal particles does not depend on the size of the particles but depends on the viscosity of the solution.

$0.27 \ g$ of a long chain fatty acid was dissolved in $100 \ cm^3$ of hexane. $10 \ mL$ of this solution was added dropwise to the surface of water in a round watch glass. Hexane evaporates and a monolayer is formed. The distance from edge to centre of the watch glass is $10 \ cm$. What is the height of the monolayer? [Density of fatty acid $= 0.9 \ g \ cm^{-3}, \pi = 3$]

Indicator type silica gel used as a dehumidifier contains