Water for Life

1) Chlorine tablets, distillation and filtration. In terms of cost, a good filter bottle or straw may be more costly as compared to distillation and the chlorine tablets. Chlorine tablets can be easily bought from convenience stores and distillation can be easily done using a portable stove and a messtin. In terms of effectiveness, a good filter may be the best option to purify water as it is able to filter out bigger unwanted particles and kill bacteria. However, it needs to be regularly replaced. Using all three methods will be the most effective in killing pathogenic bacteria and purifying water.

Similar methods used in purifying municiple water supplies are chlorination, distillation and filtration.

2) Desalination is more costly and energy intensive. It is usually done by energy rich countries.

3)

a) Corroded water pipes or pipe soldering using lead.

b) It is possible if irresposible acts lead to lead leakage into the drinking water pipes. However in most cases, the drinking water pipes are not connected to the water drainage system.

4) Water soluble vitamins are polar. They are able to form hydrogen bonds with water molecules.

Fat soluble vitamins are non-polar. They are hydrophobic and dissolve in other non-polar substances.

 

15 Feb Application Exercise

  1. The greenhouse gases trap some of the heat and retains it in the atmosphere. The increase in greenhouse gases because of pollution activities naturally causes this rise. Also, as ice melts into water, the ocean water tends to trap the heat more rather than reflecting it as ice.
  2. The statement “lowered my concerns” is incorrect. Global warming affects different part of the world differently; colder places get colder and warmer places, warmer. Hence it is wrong to attribute the presence of more snow to a lack of global warming. Further, the term “global warming” might be misleading, as it gives an impression of rising temperatures across the world; the term “climate change” should be used instead, as global warming affects different countries differently.
  3. It was unsuccessful because blasting microwave radiation at water molecules only causes the water molecules to rotate faster and generate more heat and IR radiation, instead of transmitting the signals back.
  4. In the short run, the air quality affects us the most, because we need to breathe in air. Further, the diseases that come about as a result of bad air quality lasts a whole lifetime, which makes it even worse. In the long run, global warming will affect us the most because it involves habitats, our food production and also the way we live as human beings.

8 Feb Application Exercise

1.

a) Exothermic. Requires energy to start the combustion.

b) Endothermic. Heat from the skin transfers to water on the skin. Heat is converted into kinetic energy i.e. gas molecules are moving.

c) Endothermic. Heat is added causing the molecules to move, increasing kinetic energy.

2.  For the reactants the bond strength would be weaker because less energy is required to break the bond. For the products the bond strength would be stronger resulted in more energy being released.

3. Heat is the flow of energy from hotter to colder objects. Temperature determines direction of heat flow. To give an example, the number of people in a room. Each one of us gives off heat transferring to the molecules in a room. The heat causes the molecules’ average speed to increase. Hence the rising temperature; the more people in a room, the higher the temperature.

4.

a) It has a knocking characteristics of 98% isooctane & 2% n-heptane.

b) No, we are not able to tell if it contains oxygenates.

Ozone Layer

The ozone layer or ozone shield is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet radiation.

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