What distinguishes photochemical smog from sulfurous smog?

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Multiple Choice

What distinguishes photochemical smog from sulfurous smog?

The main idea is that photochemical smog is driven by sunlight causing reactions between nitrogen oxides and volatile organic compounds, which produce ozone at ground level and other secondary pollutants. This sunlight-dependent chemistry gives the brown, straw-colored haze often seen on sunny days in polluted urban areas. Sulfurous smog, on the other hand, comes from burning coal and releasing sulfur dioxide; in humid, cool air this SO2 forms sulfate aerosols and a gray haze with potential acid deposition, and it’s not driven by sunlight. So the distinguishing feature is the light-driven NOx–VOC chemistry producing ozone in photochemical smog, versus sulfur emissions from combustion forming sulfate-rich haze in sulfurous smog.

The main idea is that photochemical smog is driven by sunlight causing reactions between nitrogen oxides and volatile organic compounds, which produce ozone at ground level and other secondary pollutants. This sunlight-dependent chemistry gives the brown, straw-colored haze often seen on sunny days in polluted urban areas. Sulfurous smog, on the other hand, comes from burning coal and releasing sulfur dioxide; in humid, cool air this SO2 forms sulfate aerosols and a gray haze with potential acid deposition, and it’s not driven by sunlight. So the distinguishing feature is the light-driven NOx–VOC chemistry producing ozone in photochemical smog, versus sulfur emissions from combustion forming sulfate-rich haze in sulfurous smog.

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