# Mercury Barometer Experiment: Atmospheric Pressure

• ftball22
In summary, the conversation is about a new member seeking help with a question regarding atmospheric pressure. The given information includes a mercury barometer and a school experiment. The goal is to find the value of atmospheric pressure in mmHg. The use of Boyle's law is suggested.
ftball22

## Homework Statement

Hi guys, I'm new here and I hope you can help me with this question that's been puzzling me for a good week now.

Mercury barometer of 1m with mercury column height of 760cm is equivalent to 1.0x10^5 Pa.
School experiment to find atmospheric pressure was as follows. Length of air trapped in capillary tube sealed at one end by thread of mercury. When horizontal, the length of trapped air column was 82mm and length of thread of mercury was 39mm. When tube held vertically with open end upwards, air column was squashed to 78mm.

Find value of atmospheric pressure in mm of mercury mmHg

## Homework Equations

Not sure if there is one
Does P=F/A help?

## The Attempt at a Solution

To be honest I really haven't had much to go in, but I can only think that gravity must be playing a part in it squashing the mercury down when it is vertical?

Any help appreciated!

Hint: consider using Boyle's law.

## 1. What is a mercury barometer?

A mercury barometer is a scientific instrument used to measure atmospheric pressure. It consists of a glass tube filled with mercury, with one end closed and the other end open. The open end is placed in a dish of mercury, creating a vacuum above the mercury in the tube. Changes in atmospheric pressure cause the level of mercury in the tube to rise or fall, allowing for the measurement of pressure.

## 2. How does a mercury barometer work?

The principle behind a mercury barometer is based on the fact that the weight of the atmosphere exerts pressure on the surface of the mercury in the dish. This pressure is balanced by the weight of the mercury in the tube, creating a column of mercury with a specific height. The higher the atmospheric pressure, the taller the column of mercury will be, and vice versa.

## 3. What is the purpose of a mercury barometer experiment?

The purpose of a mercury barometer experiment is to measure changes in atmospheric pressure. This information can be used to predict changes in weather patterns, as well as to study the behavior of gases in various conditions. It is also used in the calibration of other instruments that measure atmospheric pressure.

## 4. How do you conduct a mercury barometer experiment?

To conduct a mercury barometer experiment, you will need a glass tube, a dish of mercury, a ruler, and a container to hold the mercury. Carefully fill the tube with mercury, making sure no air bubbles are present. Place the open end of the tube in the dish of mercury and measure the height of the mercury column. Record this measurement and monitor it over time to observe changes in atmospheric pressure.

## 5. What are the potential hazards of working with mercury in a barometer experiment?

Mercury is a toxic substance, so it is important to handle it with caution when conducting a barometer experiment. Always wear gloves and avoid touching the mercury with your bare skin. Make sure to dispose of any leftover mercury properly and never pour it down the drain. If a mercury spill occurs, it should be cleaned up immediately using proper safety measures and equipment.

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