Problem 22 - Chemistry: The Central Science in SI Units, Global Edition

Question

Hurricane Wilma of 2005 is the most intense hurricane on record in the Atlantic basin, with a low-pressure reading of 882 mbar (millibars). Convert this reading into (a) atmospheres, \((\mathbf{b})\) torr, and \((\mathbf{c})\) inches of \(\mathrm{Hg}\).

Step-by-Step Solution

Answer

The pressure reading of Hurricane Wilma, 882 mbar, can be converted into the following units: (a) 0.882 atmospheres, (b) approximately 661.5 torr, and (c) approximately 26.046 inches of Hg.

Step 1: Identify the conversion factors

In order to convert the pressure from one unit to another, we need to find the appropriate conversion factors. Here are the conversion factors we need for this problem: 1 millibar (mbar) = 0.001 atm 1 millibar (mbar) = 0.750062 torr 1 millibar (mbar) = 0.029530 inches of Hg These conversion factors will help us change the pressure reading in mbar to other units.

Step 2: Convert mbar to atmospheres (atm)

We know the pressure reading in mbar and the conversion factor we need for atmospheres: Pressure in mbar = 882 mbar Conversion factor = 1 mbar = 0.001 atm To convert the pressure reading to atmospheres, we will multiply it by the conversion factor: Pressure in atm = Pressure in mbar × Conversion factor Pressure in atm = 882 mbar × 0.001 atm/mbar Pressure in atm = 0.882 atm So, the pressure reading in atmospheres is 0.882 atm.

Step 3: Convert mbar to torr

Now, we'll convert the pressure reading in mbar to torr: Pressure in mbar = 882 mbar Conversion factor = 1 mbar = 0.750062 torr Pressure in torr = Pressure in mbar × Conversion factor Pressure in torr = 882 mbar × 0.750062 torr/mbar Pressure in torr ≈ 661.5 torr Thus, the pressure reading in torr is approximately 661.5 torr.

Step 4: Convert mbar to inches of Hg

Finally, we'll convert the pressure reading in mbar to inches of Hg: Pressure in mbar = 882 mbar Conversion factor = 1 mbar = 0.029530 inches of Hg Pressure in inches of Hg = Pressure in mbar × Conversion factor Pressure in inches of Hg = 882 mbar × 0.029530 inches of Hg/mbar Pressure in inches of Hg ≈ 26.046 inches of Hg Thus, the pressure reading in inches of Hg is approximately 26.046 inches of Hg. To summarize, Hurricane Wilma's pressure reading of 882 mbar is equal to: (a) 0.882 atmospheres (b) 661.5 torr (c) 26.046 inches of Hg

Key Concepts

Atmospheric Pressure

Atmospheric pressure refers to the force exerted by the weight of the air in the Earth's atmosphere. This pressure is caused by the gravitational pull of the Earth acting on the air molecules. It plays a critical role in weather patterns and climatic conditions.

Atmospheric pressure is measured using different units. One of the most common units is the atmosphere (atm). One atmosphere is the average pressure at sea level on Earth.

This unit provides a benchmark for understanding how high or low a particular pressure reading is when comparing it to normal conditions.

For context, the pressure reading of 0.882 atm, as converted from 882 millibars (mbar) in Hurricane Wilma's case, indicates an extremely low pressure compared to the standard atmospheric pressure of 1 atm.

Low atmospheric pressures are often associated with severe weather conditions, such as hurricanes and cyclones, which is why Wilma was such an intense storm.

Millibar Conversions

Understanding millibar conversions is essential because the millibar is a unit of pressure commonly used in meteorology to express atmospheric pressure.

In many contexts, pressure readings in millibars might be converted into other units for analysis or reporting purposes.

A conversion involves multiplying the number of millibars by a specific factor to obtain the equivalent pressure in other units.

For Hurricane Wilma, the millibar value was converted into atmospheres, torr, and inches of mercury using these conversion factors:

• 1 mbar = 0.001 atm
• 1 mbar = 0.750062 torr
• 1 mbar = 0.029530 inches of Hg

When using these factors, careful calculations show how 882 mbar converts into 0.882 atm, approximately 661.5 torr, and around 26.046 inches of Hg.

The ability to perform these conversions aids in better international communication and comparison of atmospheric conditions across different regions.

Pressure Units Conversion

Pressure units conversion is a fundamental skill in many scientific and engineering fields.

Various units exist to measure pressure, including atmospheres, pascals, and inches of mercury, among others. Each unit might be used in different contexts or industries based on the standard practices.

Conversion between these units involves multiplication by a well-defined conversion factor to ensure that the measurement accurately reflects the same physical quantity in a different scale.

• To convert millibars to atmospheres: multiply by 0.001
• To convert millibars to torr: multiply by 0.750062
• To convert millibars to inches of Hg: multiply by 0.029530

These conversions are vital because they allow scientists to relate findings and results in a universally understandable form. In the case of hurricanes, converting to different units helps meteorologists and other stakeholders interpret the severity of storms, enabling appropriate preparations and responses.

Ultimately, mastering pressure units conversion ensures that data is not only accurate but also meaningful across different disciplines and geographical borders.