Acid rain Knowledge-Based Download PDF

Questions

1. 1.

   To mitigate the formation of acid rain, coal-fired power facilities utilize wet flue gas desulfurization systems to capture sulfur dioxide gas before it enters the atmosphere. Which chemical reagent is commonly introduced into the scrubber slurry to react with and neutralize this acidic gas, ultimately yielding calcium sulfate?

   • A) Calcium carbonate ($\text{CaCO}_3$)
   • B) Sodium chloride ($\text{NaCl}$)
   • C) Silicon dioxide ($\text{SiO}_2$)
   • D) Iron(III) oxide ($\text{Fe}_2\text{O}_3$)
2. 2.

   Why are freshwater ecosystems situated on granite bedrock significantly more vulnerable to acidification from acid rain than those located on limestone bedrock?

   • A) Granite bedrock lacks soluble carbonate minerals, providing negligible acid-neutralizing capacity to buffer incoming hydronium ions.
   • B) Granite bedrock rapidly releases concentrated sulfuric acid upon physical contact with surface runoff.
   • C) Limestone bedrock acts as an impermeable physical barrier that completely prevents precipitation from entering the watershed.
   • D) Limestone bedrock selectively reduces dissolved sulfate ions into insoluble elemental sulfur, removing acidity.
3. 3.

   When acid rain containing sulfuric acid comes into contact with historical monuments constructed from marble or limestone, which chemical transformation is primarily responsible for the accelerated weathering and deterioration of the stone surfaces?

   • A) Oxidation of calcium silicate into soluble silicic acid and calcium oxide
   • B) Direct reduction of calcium carbonate into elemental calcium and carbonic acid
   • C) Hydrolysis of calcium oxide into insoluble calcium hydroxide flakes
   • D) Conversion of insoluble calcium carbonate into more soluble calcium sulfate, water, and carbon dioxide
4. 4.

   Which chemical effect occurs in forest soils exposed to prolonged acid precipitation, directly leading to root toxicity and impaired nutrient uptake?

   • A) Increased retention of exchangeable calcium and magnesium ions within the upper soil horizons
   • B) Precipitation of dissolved heavy metals into insoluble silicate minerals that buffer soil pH
   • C) Biological reduction of atmospheric sulfate that causes a gradual alkalinization of soil pore water
   • D) Leaching of essential nutrient cations and mobilization of phytotoxic aluminum ions
5. 5.

   Normal rainwater has a pH of approximately 5.6 due to the dissolution of atmospheric carbon dioxide. Which pair of primary air pollutants, along with the secondary acids they generate in the atmosphere, is predominantly responsible for decreasing the pH of precipitation below this natural threshold to produce acid rain?

   • A) Carbon monoxide and methane, which oxidize in the lower atmosphere to produce concentrated carbonic acid and acetic acid.
   • B) Chlorofluorocarbons and tropospheric ozone, which photochemically decompose to yield aqueous hydrochloric acid and hypochlorous acid.
   • C) Ammonia and volatile organic compounds, which react with water vapor to generate high concentrations of nitrous acid and formic acid.
   • D) Sulfur dioxide and nitrogen oxides, which undergo atmospheric oxidation and hydration to yield sulfuric acid and nitric acid.