Question

A flask containing neon gas is connected to an open-endedmercury manometer. The open end is exposed to the atmosphere, wherethe prevailing pressure is 745 torr. The mercury level in the openarm is 50 mm below that in the arm connected to the flask of neon.What is the neon pressure, in torr?
A. -50 torr

B. 50 torr

C. 695 torr

D. 795 torr

E. None of these choices is correct.

Answer 1

Answer: Option (C) is the correct answer.

Explanation:

The given data is as follows.

          $P_{bar}$ = 745 torr

          $\Delta P$ = - 50 (the value is negative because on the open side its level is lower than the side connected to the gas)

Now, formula to calculate the pressure of neon gas will be as follows.

                 $P_{neon} = P_{bar} + \Delta P$            

Putting the given values into the above formula as follows.

               $P_{neon} = P_{bar} + \Delta P$        

                   = $745 torr + (- 50 torr)$            

                   = 695 torr

Thus, we can conclude that the neon pressure is 695 torr.