CM8001 Group 13 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13 The Water We Drink and Use Mon, 09 Apr 2018 06:56:53 +0000 en-US hourly 1 https://wordpress.org/?v=4.7.5 Application Exercise 05/04/17 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-050417/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-050417/#respond Thu, 05 Apr 2018 08:08:05 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=194 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 →

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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 body: Aspirin, Morphine, Estrogen, Amphetamine

Inhibit the growth of substances that cause infections: (Keflex) antibiotic, Penicillin

4a) Herbal supplement manufacturers can make generic claims about their products, however they usually include a disclaimer that their claims are not tested or supported by the relevant authorities. The disclaimer will also usually include that the product is ‘not intended to diagnose, treat, cure or prevent any disease’ because only regulated drugs can legally make such a claim.

b) Herbal, health supplements and alternative medicine can be sold and imported without a licence from the Health Sciences Authority. It is the manufacturer’s/ dealer’s responsibility to ensure the safety and quality of these supplements. They are also advised to comply with the guidelines set out by HSA. The authority will step in only when the guidelines have been reported to be flouted.

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Application Exercise 22/03/17 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-220317/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-220317/#respond Wed, 22 Mar 2017 07:22:48 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=154 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 →

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  • 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) In linear HDPE, the weak but extensive dispersion forces allow the molecules to slip pass one another. hence, this enables the plastic to stretch and neck, maintaining a delicate sense of touch for the gloves.
  • Polymer molecules in plastic have weak dispersion forces that allow the molecules to sip pass one another, allowing the plastic to stretch and neck. When stretched, the molecules become aligned in a way that is parallel to each other, in the direction of the pull. The thickness decrease since the 3D structure is not reversible and will continue decreasing until the plastic breaks/ tears. On the other hand, paper tears rather than stretches as cellulose molecules in the paper are held far more rigidly in place, and the molecules are not free to align.
  • a) – Remains stable over the time of use
    – Non-toxic
    – Non-soluble in body fluids
    – Non-reactive in body fluids
    b) Contact lenses can be made from different polymers such as polymethyl methacrylate (PMMA), polymacon, hioxifilcon, methanfilcon, and lidofilcon. Properties that are desirable in these materials include being permeable to oxygen, non-toxic, and can easily conform to the shape of the eyes.
    c) Hard contact lens are usually made of PMMA, which is a rigid, non-gas permeable plastic. Soft contact lenses are made of silicone, which is very flexible and allows oxygen to reach the eye. Therefore, soft contact lenses are more comfortable to wear.
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    Application Exercise 15/03/17 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-15317/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-15317/#respond Wed, 15 Mar 2017 07:39:14 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=84 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 →

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  • 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,               this implies that the pH of rainfall in the park is around pH 4 – 5, 1 unit down from the pH of natural                     rain.

    2.

    a) Laundry can be dried using a dryer which uses electricity. Electricity is generated at power stations by electro-mechanical generator which is driven by heat engines using fossil fuel. Burning of fossil fuel causes SOX to be released into the atmosphere. Thus, hanging your laundry to dry eliminate the need of using any electricity.

    b) Using personal transportation increases the production of NOX in the atmosphere. Walking, biking, and taking public transportation to work decreases the number of vehicles on the road.

    c) Multiple small loads used for dishwashers and washing machines increases the overall power used. Thus, more power must be generated at the fossil fuel power stations which will cause more SOX to be released into the atmosphere.

    d) Without insulation, more power is needed to generated enough heat to heat up and maintain the temperature of the hot water heaters and pipes. Thus, more power must be generated at fossil fuel power stations, causing increase in SOX in the atmosphere. With insulation, heat loss can be significantly reduced.

    e) Imported products and goods will be transported through land, sea or air. This uses vehicles that will produce NOX. Local grown product and food will decrease number of transportation used to delivery which help in preventing more NOX creation.

     

    3. a) Acids: HCl (hydrochloric acid), H2SO4 (sulfuric acid), H2CO3 (carbonic acid), HNO3 (nitric acid), CH3COOH                       (ethanoic acid)

    Bases: NaOH (sodium hydroxide), NH3 (ammonia), Ba(OH)2 (barium hydroxide), LiOH (lithium hydroxide),                      Be(OH)2 (beryllium hydroxide)

    b) Acids: turn blue litmus paper red, turn phenolphthalein colourless, react with reactive metals to produce                       hydrogen gas (effervescence)

    Bases: turn phenolphthalein pink, slippery feel when dissolved in water, turn red litmus paper blue.

     

    4.  In Singapore, plants and animals are going extinct due to acid rain. The pH value of water in the stream has increased by 0.3. This is not a surprise as our level of industrialisation is indeed high and also the presence of aerosols.

    The acid deposition could possibly originate both within and outside Singapore’s borders. Acid deposition from outside Singapore’s borders is inevitable as our neighbouring countries, China and India, had drastic increases in demand for manufactured goods and electricity over the last decade. However, the lack of pollution regulations in these major developing nations would continue to increase the potency for them as well as for us since acid rain cannot be simply contained by geographical borders. Acid deposition also can happen within Singapore itself as Singapore does have areas of high industrialisation (such as Jurong Island), and ships that dock in Singapore also use fuel that has been shown to have relatively high content of sulphur -containing compounds. These could potentially lead to acid rain in Singapore.

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    Application Exercise 22/02/17 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-220217/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-220217/#respond Wed, 22 Feb 2017 07:53:52 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=52 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 →

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    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 water. Common chemicals present in the tablets are iodine, chlorine or potassium permanganate. These substances kill the bacteria in water by disrupting the ionic balance within the pathogenic cells. This is a simple and inexpensive method.

    Evaporation trap- This method requires a container and plastic cover. Place a plastic cover or a large leaf over a container of water and boil the water. Water vapour condenses on the surface of the plastic cover or leaf and can be collected as purified water. However, this is not the fastest way to get potable water.

    The most cost efficient and effective method will be to use purification tablets, followed by boiling and lastly evaporation trap. The purification tablet method is the most user-friendly and with some cost (to purchase the tablets) a good volume of potable water can be obtained.

    The methods mentioned above use similar concepts of killing bacteria and harmful substances but to purify municipal water supplies, high technology machines and apparatus are required to obtain them.

     

    2. Desalination techniques require a high amount of energy to produce relatively small amount of potable drinking water. Thus, a lot of cost is involved in providing the high amount of energy, which is why other cheaper methods are more widely used.

     

    3 a. The likely major source of the lead in drinking water is due to the corrosion of lead pipes for the transportation of drinking water to the drinking fountains.

     

    3b. The research activities carried out in the chemistry building does not account for the elevated lead levels found in the drinking water. If the chemistry building has a well-developed water-related infrastructure, drinking water and water used after research activities would not be flowing in the same pipe (separated by different pipes). Therefore, the drinking water would not be contaminated by waste water produced by research activities.

     

    4. Water-soluble vitamins are soluble in polar solvents such as water. This indicates that these vitamins have several polar groups within their molecular structures and therefore are generally polar. Fat-soluble vitamins, on the other hand, are soluble in non-polar solvents such as fat tissues in the body. Therefore, these vitamins are generally non-polar, having few or no polar groups in their molecular structures.

     

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    Application Exercise 15/02/17 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-150217/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-150217/#respond Wed, 15 Feb 2017 07:33:25 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=34 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 →

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  • 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 deviated from the usual climate conditions. This deviation may possibly be due to global warming. Most likely, other parts of the Earth will be experiencing unexpected climate changes. The intensity of temperature will change drastically as warmer places will become warmer and colder places will become colder.
  • The design was not successful because the energy from microwave radiation is converted into rotational energy, which triggers the rotation of water molecules in the air. Therefore, lesser or no energy is remained in the microwave radiation to be reflected back to the radar device, making it an unsuccessful device.
  • Air quality poses a serious problem in the short run as toxic gases and air particulates are emitted from activities such as burning fossil fuels. All these emissions are in direct contact with us and therefore has an impact on our health.
    Global warming poses a serious problem in the long run as it is a phenomenon that is ongoing, where it’s effects are ever-changing. In the worst cases, it can lead to unfavourable climate conditions for human life.
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    Application Exercise 08/02/17 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-080217/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/application-exercise-080217/#respond Wed, 08 Feb 2017 07:20:51 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=32 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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    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 amount of heat energy has to be released during the explosion reaction. Hence, we want a high energy difference. Therefore, the bond strength of the reactants should be weaker than the bond strength of the products to produce a net negative energy difference.

     

    3. Heat is the total energy of the movement of all molecules in one substance while temperature the average energy of molecules in substance.

    When an ice cube melts, the temperature remains constant while heat is absorbed.

    (further illustration of the difference)

    4a) The knocking characteristics of this gasoline is 98% isooctane and 2% heptane.

    b) Merely knowing the octane number of the gasoline does not tell us whether or not it contains oxygenates. However,we do know that fuel with oxygenates have higher octane ratings, with common oxygenated fuel additives having octane ratings of over 100.

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    Today I learnt http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/today-i-learnt/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/today-i-learnt/#respond Wed, 25 Jan 2017 08:03:06 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=14 water vapour concentration vary place to place woohoo   Read more →

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    water vapour concentration vary place to place woohoodraw-cartoon-water-drop-step-4

     

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    Components of Air & PSI ~~ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/components-of-air-psi/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/components-of-air-psi/#respond Wed, 25 Jan 2017 07:56:28 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=12 It was interesting to realise that the concentration of water vapour differs significantly under different conditions. ~~  The PSI values are IMPORTANT. :)) Read more →

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    love-is-in-the-air2-1920x1080-wide-wallpapers-net

    1. It was interesting to realise that the concentration of water vapour differs significantly under different conditions. ~~
    2.  The PSI values are IMPORTANT. :))
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    First Lesson http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/first-lesson/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/first-lesson/#respond Wed, 25 Jan 2017 07:53:59 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=6 We had a quiz the moment the class started     Read more →

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    We had a quiz the moment the class starteddownload

     

     

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    Hello world! http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/hello-world/ http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/hello-world/#comments Tue, 24 Jan 2017 08:08:00 +0000 http://ossarchive.adm.ntu.edu.sg/2016-17/cm8001-group-13/?p=1 Welcome to Open Source Studio. This is your first post. Edit or delete it, then start blogging! Read more →

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    Welcome to Open Source Studio. This is your first post. Edit or delete it, then start blogging!

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