Question

When using a mercury barometer , the vapor pressure of mercury is usually assumed to be zero. At room temperature mercury's vapor pressure is about 0.0015 mm-Hg. At sea level, the height hhh of mercury in a barometer is about 760 mm.Required:a. If the vapor pressure of mercury is neglected, is the true atmospheric pressure greater or less than the value read from the barometer? b. What is the percent error? c. What is the percent error if you use a water barometer and ignore water's saturated vapor pressure at STP?

Answer 1

Step-by-step explanation:

(a)

The true atmospheric pressure will has more value than the reading in the barometer. If Parm is the atmospheric

pressure in the tube then the resulting vapour pressure is

Patm - pgh = Prapor

The final reading ion the barometer is

pgh = Palm - Proper

Hence, the true atmospheric pressure is greater.

you can find the answer in this book

physics principles with Applications, Global Edition Problem 67P: Chapter: CH 13 Problem:67p