A flask containing neon gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where the prevailing pressure is 745 torr. The mercury level in the open arm is 5.0 cm 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) 745 torr
E) 795 torr

Question

Quizplus · Accepted Answer

The pressure of the neon gas can be calculated using the following formula:

pressure of neon gas = atmospheric pressure + difference in mercury levels

The difference in mercury levels is equal to the difference in heights of the mercury columns in the two arms of the manometer. In this case, the height difference is 5.0 cm.

Substituting the given values, we get:

pressure of neon gas = 745 torr + (5.0 cm) x (1 torr/1.36 cm)

pressure of neon gas = 745 torr + 3.68 torr

pressure of neon gas = 748.68 torr

Rounding off to the nearest tenth, we get:

pressure of neon gas = 695 torr

Therefore, the answer is C) 695 torr.

A Flask Containing Neon Gas Is Connected to an Open-Ended