1a. Coal-fired plants produce massive amounts of sulphur dioxide. These compunds then react with other compunds in the air to form fine particles that reduce the overall visibility. Sulphuric acid from coal burning form tiny droplets by reacting with the water vapour, which does not absorb sunlight, causing even poorer visibility.
1b. Naturally, rain is slightly acidic, with a pH of about 5.5. Every time a pH value drops by 1, it means that the concentration of positive H ions will be 10 times higher. Therefore, the average rainfall in the park is now 5.5 – 1 = 4.5.
2a. Hanging out the laundry to dry it instead of using a dryer helps save electricity. This in turn reduces the energy required by households and results in the decrease of the burning of fossil fuels if done by the masses. Less of the harmful pollutants such as SO2 and NOx, which reacts with the environment to produce acid rain, will thus be produced by the power plants.
2b. Walking, cycling or taking the public transport in place of driving one’s own vehicle reduces the amount of harmful gases such as NOx and SO2 being produced. As NOx and SO2 are the main chemicals involved in the production of acid rain, with less of them present in the environment, the amount of acid rain produced would consequentially decrease.
2c. This is to save electricity as the machines will be used less frequently. As electricity is generated by the burning of fossil fuels, reducing the energy usage will result in less burning of fossil fuels. As a result, less pollutants are produced and present in the atmosphere hence reducing acid rain. This will lower the amount of SOx gas produced in the process and reduces acid rain.
2d. By insulating the pipes and heaters, we reduced the heat loss to environment. This decreases the amount of energy required to maintain the heat hence saving electricity by using fossil fuels. Lower energy consumption will lead to lower coal burning and lower SOx gas formed.
2e. By buying local food, our carbon footprint is reduced as there will be a low demand of air mail delivery services across countries. This results in lesser pollutants formed such as NOx gas from the engines of airplanes and ships, which will contribute to the acid rain.
3a. Acids: Hydrochloric acid (HCl), Nitric acid (HNO3), Sulfuric acid (H2SO4), Phosphoric acid (H3PO4) and Acetic acid (CH3COOH)
Bases: Sodium hydroxide (NaOH), Potassium hydroxide (KOH), Calcium hydroxide (Ca(OH)2), Magnesium hydroxide (Mg(OH)2) and ammonium hydroxide (NH4OH)
3b.
– Both acids and bases are soluble in water (no suspension/cloudy mixture).
– Both acids and bases conduct electricity (light bulbs light up).
-Acids turn blue litmus paper red while bases turn red litmus paper blue.
4. Acid rain could be driving Singapore’s remaining native species to extinction. Acid rain falls into the water bodies and lowers the pH level of the water bodies. As mentioned in the Lecture slides, healthy lakes have a pH of 6.5 or slightly above. If the pH is lowered below 6.0, fish and other aquatic life are affected. Due to acid rain, as mentioned in the article, 20 species of animals plentiful in the Singapore’s Bukit Timah Nature Reserve in the 1980s, including frogs, crabs and fish, are slowly being wiped out.
Amresh Gunasingham, September 2009. Native Species may be wiped out by acid rain.Taken from: http://newshub.nus.edu.sg/news/0909/PDF/ACIDRAIN-st-14Sep-pB1.pdf
The acid deposition originate both outside and inside the Singapore’s borders. Under the local polluters, as mentioned in the article, the sources of sulfur dioxide (SO2) are included motor vehicles, refineries, power station, shipping and other industries. Diesel vehicles make up of half of all PM 2.5 emission in Singapore. Foreign pollution plays a part in the acid deposition.
Feng Zengkun, March 2014. Pushing for higher air quality. Taken from: http://www.straitstimes.com/singapore/pushing-for-higher-air-quality\
