If a volatile liquid is added to a sealed flask, the total pressure inside the flask is a sum of the air pressure and the vapor pressure of the liquid. Consider a flask at 298 K with an air pressure of 738 mmHg to which some n-butanol is added. If the measured pressure after the addition is 746 mmHg, what is the vapor pressure of n-butanol at 298 K

Explanation:

Total pressure inside flask = air pressure + vapour pressure of butanol

746 = 738 + vapour pressure of butanol

vapour pressure of butanol  = 8 mm Hg .

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

2b2t

explanation:

2b2t