- 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.
- The NPCA reported “the average rainfall in 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.
- What is the connection between coal-fired plants and poor visibility?
- Coal-fired plants release sulfuric acid, which forms tiny droplets. These droplets are suspended in air, forming aerosols which do not absorb sunlight. Instead, aerosols reflect sunlight and reduce visibility.
- Since the rainfall is 10 times more acidic than natural, it contains 10 times H+ ion concentration. The pH, therefore, falls by 1. The average pH of rain is 5-6, so the pH of rainfall in the park is 4-5.
- Here are examples of what an individual might do to reduce acid rain. For each, explain the connection to producing acid rain.
- Hang your laundry to dry it.
- Walk, bike, or take public transportation to work.
- Avoid running dishwashers and washing machines with small loads.
- Add additional insulation on hot water heaters and pipes.
- Buy locally grown and locally produced food.
Reducing acid rain is possible by reducing the electricity and vehicle usage. Electricity generation in power plants requires the burning of fossil fuels and coal, same as vehicles which run on fossil fuels. The combustion of fossil fuels and coal emits SOx and NOx gases which could react and cause the acid rain. Therefore, reducing both usage could reduce acid rain. The following activities could reduce acid rain by reducing electricity and vehicle usage.
- Hanging laundry to dry it reduces the electricity used in a household.
- Walking, cycling or taking public transportation reducing the usage of private vehicles.
- Avoid running dishwasher and washing machines with small loads to reduce the electricity usage.
- Adding additional insulation prevents heat loss in water heaters and pipes, therefore it reduces the electricity used.
- Buying locally grown and produced food cuts the transportation process in buying food from other places which means avoiding more vehicle usage.
3.
- Name three observable properties generally associated with acids and bases.
- Give names and chemical formulas for five acids and five bases.
| Acid | Base |
| HCl (hydrochloric acid) | NaOH (sodium hydroxide) |
| HNO3 (nitric acid) | Mg(OH)2 (magnesium hydroxide) |
| H2SO4 (sulfuric acid) | Ca(OH)2 (calcium hydroxide) |
| H3PO4 (phosphoric acid) | NH3 (ammonia) |
| CH3COOH (acetic acid) | KOH (potassium hydroxide) |
| Acid | Base |
| sour taste | bitter taste |
| turn blue litmus red | turn red litmus blue |
| frequently burns nose | slippery feel |
4. The concerns of acid rain vary across the globe. Many countries in 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?
URLs:
Just like any other countries, Singapore faces the threat of acid rain, especially since Singapore has low basic content of soil, the neutralization of acidity is low. The acid deposition itself originates outside and inside Singapore. One of the transboundary sources is the forest fires in neighbouring country, Indonesia, which release high level of carbon dioxide and sulfur dioxide which react with water producing carbonic acid and sulfuric acid. The industry and urban areas in Singapore also produce gases which cause acid rain.
The effects of acid rain in Singapore are seen in the increase of acidity of streams and the higher risk of extinction faced by native species in Singapore. The number of several Singapore native species such as Singapore freshwater crab have declined drastically.