As of the writing of this text, EPA standards limit atmospheric ozone levels in urban environments to 84 ppb. How many moles of ozone would there be in the air above Los Angeles County (area about 4000 square miles; consider a height of 100 m above the ground) if ozone was at this concentration?

Verified step by step guidance

Convert the area of Los Angeles County from square miles to square meters. Use the conversion factor: 1 square mile = 2.59 x 10^6 square meters.

Calculate the volume of the air column above Los Angeles County by multiplying the area in square meters by the height of the column (100 meters).

Convert the ozone concentration from parts per billion (ppb) to a molar concentration. Assume standard conditions (1 atm, 298 K) and use the ideal gas law to find the molar volume of air.

Calculate the total number of moles of air in the volume calculated in step 2 using the molar volume from step 3.

Determine the number of moles of ozone by multiplying the total moles of air by the concentration of ozone in moles per mole of air (from step 3).

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Molar Volume of a Gas

At standard temperature and pressure (STP), one mole of an ideal gas occupies approximately 22.4 liters. This concept is crucial for converting between moles and volume, especially when dealing with gases like ozone in atmospheric calculations.

Concentration Units

Concentration can be expressed in various units, including parts per billion (ppb). In this context, 84 ppb means there are 84 molecules of ozone per billion molecules of air, which is essential for determining the total amount of ozone in a given volume of air.

Volume Calculation

To find the total volume of air above a specified area, one must calculate the volume using the area and height. For Los Angeles County, the volume can be calculated by multiplying the area (in square meters) by the height (in meters), which is necessary for determining the total moles of ozone present.

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Textbook Question

In 1986 an electrical power plant in Taylorsville, Georgia, burned 8,376,726 tons of coal, a national record at that time. (b) If 55% of the SO₂ could be removed by reaction with powdered CaO to form CaSO₃, how many tons of CaSO₃ would be produced?