Sunil Kumar FP
Last Activity: 10 Years ago
ANS:-(D)
When the gas is colleced over the water, it becomes moist due to presence of small quantity of water vapour caused by evaporation.
Then, pressure exerted by moist gas = pressure exerted by dry gas + pressure of water vapour (aqueous tension).
i.e. Patmospheric = Pdry + f (aqueous tension)
or, Pdry = Patmospheric – f
Therefore, aqueous tension should be subtracted from the total pressure to get pressure of the dry gas.