If the atmospheric pressure is 0.995 atm, what is the pressure of the enclosed gas in each of the three cases depicted in the drawing? Assume that the gray liquid is mercury. (i)

Key Concepts

Atmospheric Pressure

Atmospheric pressure is the force exerted by the weight of air above a given point, typically measured in atmospheres (atm) or pascals (Pa). At sea level, standard atmospheric pressure is defined as 1 atm, which is equivalent to 101.3 kPa. In this question, the atmospheric pressure of 0.995 atm indicates that the pressure exerted by the surrounding air is slightly less than standard conditions, which will affect the pressure readings of the enclosed gas.

Hydrostatic Pressure

Hydrostatic pressure refers to the pressure exerted by a fluid at equilibrium due to the force of gravity. It is calculated using the formula P = ρgh, where P is the pressure, ρ is the fluid density, g is the acceleration due to gravity, and h is the height of the fluid column. In this scenario, the height of the mercury column will influence the pressure of the enclosed gas, as the weight of the mercury will exert a downward force.

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, such as mercury, where the difference in liquid height between the two arms indicates the pressure difference. In this question, the manometer's readings will help determine the pressure of the enclosed gas relative to the atmospheric pressure of 0.995 atm.