1.Mammoth Cave National Park in Kentucky is in close proximity to the coal-fired electric utility plants in the Ohio Valley. Noting this, the National Parks Conservation Association (NPCA) reported that this national park had the poorest visibility of any in the country.
a) What is the connection between coal-fired plants and poor visibility?
Coal-fired plants release sulfur dioxide, creating sulfate particles that are responsible 60 to 85 percent of the poor visibility in the eastern parks.
b) The NPCA reported “the average rainfall in the Mammoth Cave National Park is 10 times more acidic than natural.” From this information and that in your text, estimate the pH of rainfall in the park.
Normal rain has a pH range of 5-6, so if the rainfall in this park is 10 times more acidic, the pH range must be 4-5.
2. Here are examples of what an individual might do to reduce acid rain. For each, explain the connection to producing acid rain.
a. Hang your laundry to dry it
Hanging laundry to dry requires less energy than using a clothes dryer. For an electric dryer, cutting down on energy use cuts down on the need for power companies to produce electricity by burning coal, reducing SO3 emissions
b. walk, bike, or take public transportation to work
Any of these options reduce the amount of gasoline used cutting down on NO emissions and thus contributing less to the acidity of rain.
c. Avoid running dishwashers and washing machines with small loads.
Using dishwashers and washing machines with large loads reduces the energy per unit load, therefore needing power companies to produce less electricity by burning coal, reducing SO3 emissions
d. Add additional insulation on hot water heater and pipes
Adding insulation on hot water heater pipes reduces heat loss, as well the need for power companies to produce electricity to generate more heat by burning coal, reducing SO3 emissions
e. Buy locally grown produce and locally produced food.
Buying locally grown produce and locally produced food reduce the amount of gasoline used for food import and therefore cutting down on NO emissions and thus contributing less to the acidity of rain.
3. a) Gives names and chemical formulas for five acids and five bases.
Possibilities of acids include nitric acid (HNO3), hydrochloric acid (HCl), sulfuric acid (H2SO4), sulfurous acid(H2SO3) and phosphoric acid (H3PO4). Possibilities of bases include sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonium hydroxide (NH4OH), magnesium hydroxide (Mg(OH)2) and calcium hydroxide (Ca(OH)2).
b) Name three observable properties generally associated with acids and bases.
In general, acids turn blue litmus paper red, are corrosive to metals such as iron and aluminium, and release carbon dioxide from a carbonate. These properties may not be observed if the acid is not sufficiently concentrated. Bases turn red litmus paper blue, have a slippery feel in water, and are caustic to the skin.
4. The concerns of acid rain vary across the globe. Many countries in the North America and Europe have websites dealing with acid rain. Either search to locate one (“Canada, acid rain”) or use these links to websites in Canada, the UK, or Europe. What are the issues in Singapore? Does the acid deposition originate outside or inside the Singapore’s borders?
The Indonesian forest fires that took place from August through October 1997 released large amounts of gaseous and particulate pollutants into the atmosphere. The particulate emissions produced a plume that was easily visible by satellite and significantly affected regional air quality in Southeast Asia. This prolonged haze episode provided an unprecedented oppurtunity to examine the effects of biomass burning on regional atmospheric chemistry. A comprehensive study assessed the influence of biomass burning impacted air masses on precipitation chemistry in Singapore. Major inorganic and organic ions were determined in 104 rain samples collected using an automated wet-only sampler from July through December 1997. Mean pH values ranged from 3.79 to 6.20 with volume-weighted mean of 4.35. There was a substantially large number of rain events with elevated concentrations of these ions during the biomass burning period. The relatively high concentrations of sulphate, nitrate and ammonium ions observed during the biomass burning period are attributed to a long residence time of air masses, leading to progressive gas to particle conversion of biomass burning emission components. The decrease on pH of precipitation in response to the increased concentrations of acids is only marginal, which is ascribed to neutralization of acidity by ammonia and calcium carbonate.