References

 

Introduction

  • Total energy consumption 2019-2014. (2016, May 18). Retrieved March 29, 2017, from https://www.ema.gov.sg/cmsmedia/Publications_and_Statistics/Statistics/13RSU.pdf

Chemical Concept

  • U.S. Energy Information Administration – EIA – Independent Statistics and Analysis. (n.d.). Retrieved March 29, 2017, from https://www.eia.gov/tools/faqs/faq.cfm?id=73&t=11
  • Hydrocarbon combustion. (n.d.). Retrieved March 29, 2017, from http://energyeducation.ca/encyclopedia/Hydrocarbon_combustion#cite_note-3
  • Reporter, S. (2016, February 11). World Energy Day 2014: How Much Oil is Left and How Long Will it Last? Retrieved March 29, 2017, from http://www.ibtimes.co.uk/world-energy-day-2014-how-much-oil-left-how-long-will-it-last-1471200
  • Fossil Fuels. (n.d.). Retrieved March 29, 2017, from http://www.chemistryexplained.com/Fe-Ge/Fossil-Fuels.html#ixzz4bNfGlCOA

Implications

  • Society, N. G. (2013, January 14). Petroleum. Retrieved March 29, 2017, from http://www.nationalgeographic.org/encyclopedia/petroleum/
  • Nwf. “How You Can Help Wildlife Impacted by the BP Oil Spill – National Wildlife Federation.” N.p., n.d. Web. 29 Mar. 2017.
  • Adebayo, Abdulrauf Rasheed, and Bassam Tawabini. “Hydrocarbon Exploration and Production- a Balance between Benefits to the Society and Impact on the Environment.” OMICS International. OMICS International, 27 Apr. 2012. Web. 29 Mar. 2017.

 

Unit 7: Application Exercise 7

  • When Styrofoam packing peanuts are immersed in acetone (the primary component in some nail-polish removers), they dissolve. If the acetone is allowed to evaporate, a solid remains. The solid still consists of Styrofoam, but now it is solid and much denser. Explain. Hint: Remember that Styrofoam is made with foaming agents.

Answer:

Acetone dissolves the polymer, allowing the gas of the foaming agent to escape. The polymer collapses on itself and is more dense because the gas has been removed.

 

  • Consider Spectra, Allied-Signal Corporation’s HDPE fiber, used as liners for surgical gloves. Although the Spectra liner has a very high resistance to being cut, the polymer allows a surgeon to maintain a delicate sense of touch. The interesting thing is that Spectra is linear HDPE, which is usually associated with being rigid and not very flexible.

a. Suggest a reason why branched LDPE cannot be used in this application.

b. Offer a molecular level reason for why linear HDPE is successful in this application.

Answer:

a. LDPE cannot be used in this application because it does not have required strength.

b. The molecules of HDPE must line up in a way that produces the required strength. Using a thin linear of HDPE allows sufficient flexibility.

 

  • When you try to stretch a piece of plastic bag, the length of the piece of plastic being pulled increases dramatically and the thickness decreases. Does the same thing happen when you pull on a piece of paper? Why or why not? Explain on a molecular level

Answer:

When the piece of plastic is stretched , the strip narrows and “necks down”. The molecules become aligned parallel to each other and in the direction of the pull. This alteration of the three-dimensional structure is not reversible, and if the pulling continues, the plastic breaks. When the same pulling force is applied to a piece of paper, the paper tears rather than stretching to any significant extent. The cellulose molecules in paper are held far more rigidly in place, and are not free to become aligned.

 

  • A Teflon ear bone, fallopian tube, or heart valve? A Gore-Tex implant for the face or to repair a hernia? Some polymers are biocompatible and now used to replace or repair body parts.

a. List four properties that would be desirable for polymers used within the human body

b. Other polymers may be used outside your body, but in close contact with it. For example, no surgeon is needed for you to use your contact lenses-you insert, remove, clean, and store them yourself. From which polymers are contact lenses made? What properties are desirable in these materials? Either a call to an optometrist or a search on the Web may provide some answers.

c. What is the difference in the material used in “hard” and ” soft” contact lenses? How do the differences in properties affect the ease of wearing of contact lenses?

Answer:

a. (1) Stable over time of intended use, (2) non-toxic, (3) ease of implantation, (4) low cost.

b. Several different types of contact lenses are on the market and each uses a different type of polymer. Polymethyl methacrylate (PMMA), one of the earliest polymers used for rigid gas permeable lenses, is structurally similar to Lucite and plexiglass. Silicone-acrylate materials now are more commonly used under trade names such as Kolfocon. Newer rigid gas permeable (RGP) polymers contain fluorine: fluoro-silicone-acrylate polymers and fluoro-silicones. Polymacon (38% water) is typical of the polymers used for soft lenses and is a polymer of 2-hydroxyethyl methacrylate (HEMA). Other methacrylates include hioxifilcon (48% water) and methafilcon (55% water) or even lidofilcon (70% water). Desirable properties include being non-toxic, permeable to oxygen, comfortable to wear, and not expensive. The ability to conform to the shape of the eye and to be easily cleaned are also desirable.

c. Hard contact lenses are typically made of PMMA, a rigid non-gas permeable plastic. The soft contact lenses that replaced them are made of silicone, which is flexible and allows oxygen to reach the eye. Because of these properties, the soft lenses tend to be more comfortable.

Unit 6: Application Exercise 6

(Q1) Mammoth Cave National Park in Kentucky is in close proximity to the coal-fired electric utility plants in the Ohio Valley. Noting this, the National parks Conservation Association (NPCA) reported that this national park had the poorest viability of any in the country.
(a)What is the connection between coal-fired plants and poor visibility?

Coal contain varying amount of sulfur, burning coal produces varying amount of Sulfur dioxide and soot. These particles blocked sunlight, and cause poor visibility.

(b)The NPCA reported “the average rainfall in Mammoth Cave National Park is 10 times more acidic than natural.” From this information and that in your text, estimate the pH of the rainfall in the park.”

Knowing that every step on the pH scale is a change by a factor of 10 and the normal rain has a pH range from 5-6.
When the average rainfall is 10 times more acidic, we can estimate that the pH of the rainfall must be around 4-5.

(Q2) Here are the examples of what an individual might do to reduce acid rain. For each, explain the connection to producing acid rain.
(a) Hang your laundry to dry it
(b) Walk,  bike, or take public transportation to work.
(c) Avoid running dishwashers and washing machines with small loads.
(d) Add additional insulation on hot water heaters and pipes.
(e) Buy locally grown produce and locally produced food.

The key is to reduce the amount of energy (such as electricity/petroleum) used in the process, because electricity comes from burning of coal or fossil fuels which releases product such as sulfur dioxide and nitrogen dioxide. These pollutant gases are in involved in the formation of acid rain. Therefore, by using lesser energy –> lesser pollutant gas –> lesser pollutant gas involved in formation of acid rain. Vehicles also uses energy and releases oxides of nitrogen which are involved in formation of acid rain too.

(a) Drying clothes naturally allow you to use less energy as compared with a clothes dryer which uses electricity.

(b) It is more eco-friendly to walk, bike or take public transport to work, because it does not produce or releases as much pollutant gases. Owning a car which can carry 4 or 5 person is not as efficient as taking a public transport which can carry more person and the amount of pollutant gas that is released are approximately the same.

(c) Using dishwasher consumes electrical energy which is not favourable. Washing machines with small loads compared with big loads is a waste of energy, as washing machines consume the same amount of water and electricity, regardless the amount of clothes.

(d) Adding additional insulation helps to warm the water constantly. This uses less electrical energy when you do not have to warm the water every time.

(e)  Buying locally grown produce and produced food will prevent vehicles that transport goods (e.g. food) from travelling a long distance. This allow lesser energy to be used in the process of transporting goods and lesser pollutant gas released in the process.

(Q3a)Give names and chemical formulas for five acids and bases.
Acids Bases
Nitric Acid, HNO₃ Sodium Hydroxide, NaOH
Hydrochloric Acid, HCl Potassium Hydroxide, KOH
Sulfuric Acid, H₂SO₄ Ammonium Hydroxide, NH₄OH
Phosphoric Acid, H₃PO₄ Magnesium Hydroxide, Mg(OH)₂
Carbonic Acid, H₂CO₃ Calcium Hydroxide, Ca(OH)₂
(Q3b)Name three observable properties generally associated with acids and bases.
Properties of an acid Properties of a base
Sour Bitter
Turn litmus paper blue to red Turn litmus paper red to blue
Sticky Slippery
The concerns of acid rain vary across the globe. Many countries in North America and Europe have websites dealing with acid rain. Either search to locate one (“Canada acid rain”) or use these links to website in Canada, the UK, or Europe. What are the issues in Singapore? Does the acid deposition orignate outside or inside the Singapore’s borders?

 

Acid rain causes extinction to some native species in Singapore by lowering the pH of the rivers and disrupting their homes.

The acid deposition originate from outside of the Singapore’s border. In the recent years, Indonesia have been burning their forest , with prevailing wind present, it actually blew particles towards Singapore, and cause haze. Haze will eventually lead to acid rain which poses a threat to the natural habitat and damage infrastructure

Application

Introduction

How to obtain petroleum and natural gases

Pros and Cons of using petroleum and natural gases

Unsustainable

 

Application

For transportation – Petroleum

Industrial-use, Cooking – natural gas

 

Alternative

For transportation – biogas, diesel, electric

Cooking – electric

 

Meeting Logs

9th March 2017

Location: Northspine Food court, 3-4 pm on 9th March 2017

Attendance:  Wind, Lemuel, Kathy, Anjana, Wan Rui, Kevin

Topics discussed: Blog layout, Content of video

Tasks to be done: Research for content of the chemical concept

Plan of action: Research for information and prepare script for video.


15th March 2017

Location: LT23, after class on 15th March 2017

Attendance:  Wind, Lemuel, Kathy, Anjana, Wan Rui, Kevin

Topics discussed: Discussed application exercises and assigned tasks regarding blog and video

Tasks to be done: Each person compiles information based on the assigned category – introduction, chemical concepts and implications. 

Plan of action: All the information should be updated on the Google doc by next week


22nd March 2017

Location: LT 23, after class on 22nd March 2017

Attendance:  Wind, Lemuel, Kathy, Anjana, Wan Rui, Kevin

Topics discussed: Discussed application exercises and blog

Tasks to be done: Create the basic layout for the blog

Plan of action: All the content should be updated on the blog and formatted


29th March 2017

Location: Northspine Food court, 1:30-4:30 pm on 29th March 2017

Attendance:  Wind, Lemuel, Kathy, Anjana, Wan Rui, Kevin

Topics discussed: LAMS, blog and videos

Tasks to be done: Complete blog and the first video 

Plan of action: Compile information for both blog an video and complete the tasks today. 

 

Chemical Concept

Petroleum and natural gas

The use of petroleum and natural gas is very prevalent in our society today. However the use of petroleum and natural gas is not sustainable. On this blog we would explore the advantages and disadvantages of using petroleum and natural gas, their increasing demand and finding alternative sources of fuel.

Petroleum is an extremely complex mixture of hydrocarbons, which can be separated into liquid (oil) and gas fractions.

Different fossil fuels have different composition of hydrocarbons. Natural gas has a composition of over 90% hydrocarbons, of which they are mostly the smallest hydrocarbons. Oil tends to be made up of medium sized hydrocarbon molecules, however the composition varies depending on the grade.

Example of multi-stage steam turbine generator process works
Example of multi-stage steam turbine generator process works Image obtained:http://www.mpoweruk.com/images/steam_turbine.gif

Petroleum is used in the production of energy, plastics and many other petrochemicals. However we are mainly concerned with the use of petroleum for electricity generation.
There are 3 main technologies in which petroleum is used to generate electricity.

Conventional steam turbine where oil is burned to heat water to create steam to generate electricity.

Combustion turbine is another technology where oil is burned under pressure to produce hot exhaust gasses which then spin a giant turbine to generate electricity.

The third technology, combined cycle technology, is a combination of the first two, where the oil is burned under pressure to generate the exhaust gases to spin the first turbine. After that the exhaust gas is recovered and used to heat water in boiler, creating steam to drive the second turbine.
The combustion of hydrocarbons CxHy follows the general formula
CxHy + (x+y/4)O2  -> xCO2 +  (y/2)H2O

e.g CH4 + 2O2 -> CO2 + 2H20

 

Air pollution due to waste gasses from power plants Image obtained: http://theearthproject.com/wp-content/uploads/2016/01/Fossil-fuels-burning-1024×680.jpg

The problem with burning fossil fuel for generating electricity is that it is not sustainable as the oil reserves is not infinite and will run out eventually. In June 2014, BP released estimates that global oil reserves will provide us 53.3 years of oil at current production rates.
The second issue with burning fossil fuels is that it produces a lot of pollutants.  The US Energy information administration estimates that to produce 293.1 kWh of electricity, 70 kg of CO2 is produced. CO2 is a greenhouse gas which contributes to global warming.