The most common desalination techniques are distillation and reverse osmosis. It requires energy for both techniques to remove salts from seawater. Hence, the techniques are inherently expensive. If there is a cheaper alternative available (for example: buying fresh water from other sources), the cheaper alternative will be considered. Thus, the reason why desalination techniques are not used widely is because of its expensive cost.

To be water-soluble, the solute has to be polar as well since water is in polar form. Thus, soluble vitamins are polar. However, being fat-soluble means the solute is not polar. Therefore, fat-soluble compounds, such as lipids, are not soluble as they cannot form hydrogen bonds with water molecules.

a. Instead of using a washing machine to dry laundry, no additional energy is used to dry the clothes which will reduce the nitrogen oxide and sulfur dioxide emissions.

b. This will reduce the number of vehicles on the road, thus reducing nitrogen oxide and sulfur dioxide emissions.

c. When we avoid running dishwashers and washing machines with small loads, we are saving huge amount of water and electricity. Since sulfur dioxide and nitrogen oxide are produced by electric powered generator, we are reducing its emissions.

d. It prevents heat loss and reduces the amount of energy to be produced.

e.This will reduce the transportation to Singapore and it will reduce the emissions of pollutants produced by transportation.

Coal plants release huge amount of water vapor along with the combustion process. The hydrogen and carbon in the coal make at least twice the amount of water vapor as the coal burnt. When the water vapor cooled in the Hill Forest area of this national park, the water vapor will become fog (formation of droplets of liquid/solid particles suspended in the air). The fog will not absorb sunlight and will instead reflect it. This reduces the visibility.

b. Since the neutral PH of rain is 7 and being 10 times more acidic will reduce PH by 1, the PH of rainfall in park will be 6.