An open-end manometer containing mercury is connected to a container of gas, as depicted in Sample Exercise 10.2. What is the pressure of the enclosed gas in torr in each of the following situations? (a) The mercury in the arm attached to the gas is 15.4 mm higher than in the one open to the atmosphere; atmospheric pressure is 0.985 atm.

Verified step by step guidance

1. Convert the atmospheric pressure from atm to torr using the conversion factor: 1 atm = 760 torr.
2. Calculate the pressure of the gas by adding the difference in mercury levels to the atmospheric pressure, since the mercury level is higher on the side open to the atmosphere.
3. Express the pressure of the gas in torr by adding the converted atmospheric pressure to the height difference in mm of mercury.
4. Ensure the units are consistent throughout the calculation, particularly when adding pressures.
5. Review the setup to confirm that the pressure difference is correctly accounted for, considering the direction of mercury displacement.

Key Concepts

Manometer

A manometer is a device used to measure the pressure of a gas by comparing it to atmospheric pressure. It typically consists of a U-shaped tube filled with a liquid, often mercury, where the difference in height between the two arms indicates the pressure difference. Understanding how to read a manometer is crucial for determining the pressure of gases in various applications.

Atmospheric Pressure

Atmospheric pressure is the pressure exerted by the weight of the atmosphere at a given point. It is commonly measured in atmospheres (atm), torr, or mmHg. In the context of the manometer, knowing the atmospheric pressure allows for the calculation of the gas pressure by adding or subtracting the height difference of the mercury column, depending on the configuration.

Pressure Conversion

Pressure conversion involves changing pressure measurements from one unit to another, such as from atmospheres to torr. The conversion factor between these units is essential for solving problems involving gas pressure. For instance, 1 atm is equivalent to 760 torr, which is necessary for accurately determining the pressure of the gas in the manometer scenario presented.