Question

The height a barometer rises depends on the absolute pressure minus its vapor pressure. What height will a barometer rise if atmospheric conditions are 14.2 psia and 68 F and the fluid is ethyl alcohol?

Answer 1

Using, P(atm) = rgh – equation 1

Where, P(atm) = Pressure in atmosphere

            r(rho) = density of the fluid filled in barometer = 0.79 gm/ mL for ethanol

g = acceleration dur to gravity specific to the geographical location = 9.8 ms^-2

h = height of the fluid level in barometer.

Given , p = 14.2 psia = 0.966 atm            [use, 1 psia = 0.068 atm.]

Putting the values in equation 1

            0.966 atm = (0.79 gm/ mL) x (9.8 ms^-2) x h

            Or, h = 0.1247 meter

            Or, h = 12.47 cm

Hence, height of ethanol level in barometer = 12.47 cm.