Application Exercise 05/04/17

1a) C5H9N3 b) c) The N-H bonds in histamine make the compound water-soluble 2a) C16H21N3 b) Ethylamine Moiety -(-CHCH2N-)- is the structure that is found in both histamine and antihistamine. Therefore, both histamine and antihistamine have similar configuration to bind to receptor sites. The similarity in configuration allow antihistamine to compete with histamine. 3) Produce a physiological response in the… Read more →

Application Exercise 22/03/17

Styrofoam packing peanuts are filled with air pockets. When dissolved in acetone, the air trapped in the Styrofoam will be released. Thus, when acetone has evaporated, remaining polystyrene will be much denser. a) Branched LDPE is soft and not very strong and hence has a low resistance to being cut. Therefore, branched LDPE cannot be used in this application. b)… Read more →

Application Exercise 15/03/17

a) Coal-fired plants produce SOx gases, which combine with water in rain to form sulfuric acid. These molecules of sulfuric acid form tiny droplets (aerosols), which reflect sunlight instead of absorbing sunlight, and hence reduces visibility. b) Since the average rainfall in the park is 10 times more acidic than natural rain, which is around pH 5 – 6,    … Read more →

Application Exercise 22/02/17

1. Boiling- Water can be boiled over a campfire. Bacteria is killed by high boiling temperature but boiling on its own may not get rid of harmful chemicals present in the water. If water is boiled over a campfire, little cost is needed but hikers have to know how to start a fire. Purification tablets – Add purification tablets to… Read more →

Application Exercise 15/02/17

The Earth is not cooling rapidly because of the presence of greenhouse gases such as CH4, H2O, CO2, nitrous oxides. These greenhouse gases absorb infrared radiation, which warms the Earth, increasing the Earth’s average temperature. The statement is incorrect. From the photo, it seems that there is more snow cover during this winter, which indicates that the climate conditions has… Read more →

Application Exercise 08/02/17

1a) It is an exothermic process. This is because heating energy is released during the process. b) It is an endothermic process. This is because heat energy is absorbed during the process. c) It is an endothermic process. This is because heat energy is absorbed to melt ice to water.   2. In order to make a good explosion, large… Read more →

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