PBL 3Photon-molecule interaction

Objectives To apply the basic concepts of photon (electromagnetic wave) and molecules in the liquid phase To explain the Lambert-Beer relationship and its application in qualitative and quantitative analysis of organic chemicals To explain in qualitative terms various spectra (uv, visible, infra red) and the functional group

Assignment 1Milk is a drink that contains almost all of food nutrients, especially proteins. Milkis the primary source ofnutritionfor young mammals before they are able todigestother types of food. Milk can be contaminated through food that eaten by livestock. In an article of Brazilian newspaper, its mention that a factory producing lead ingots, located in Caapava, caused lead and cadmium contamination of the environment, in the Paraiba Valley region of Southeastern, Brazil, through the discharge of industrial waste and the recycling of batteries. The factory, set in a rural, dairy cattle breeding area, worried sanitary authorities who envisaged the possibility of these metals' having entered the food chain. For the purpose of assessing the levels of contamination of the milk produced in the region, due to the cattle's possible consumption of contaminated grass and water, the amounts of cadmium and lead present in the milk were verified. Milk is a drink that contains carbohydrate, protein, fats, and minerals. All of those could be analyzed by spectroscopy.

1. What do you know about this graph in below? What is effect the wavelength toward the energy? Any difference between UV and visible? Explain in detail.

2. What is photon-molecule interaction and explain the ionization process and excitation process as the result of photon-molecule interaction. Explain processes/effects of photon-molecule interaction, namely photoabsorption, photon scattering, and pair-production processes.3. In photon-molecule interaction, there are two types of photon scattering: Rayleigh Scattering (elastic scattering) and Compton Scattering (inelastic scattering). What do you know about the Rayleigh Scattering and Compton Scattering? Any difference between elastic scattering and inelastic scattering?4. What is photonuclear reactions in photon-molecule interaction. Explain5. In the case above, the content of proteins could be analyzed by UV-Vis Spectroscopy. Explain the principles of UV-Vis Spectroscopy or the mechanism of the interaction between UV-Vis and proteins. And in what wavelength, proteins could absorb UV-Vis.6. What is chromophore and auxochrome and how they contribute to UV-Vis absorption by organic molecule. Explain? Identify three types of chromophore which is in the form of double bond and explain how they contribute to UV-Vis absorption.7. Determine max (the maximum wavelength) of below compound using the rule of Wood Ward-Fisher.

Assignment 2On August 21, 2009, theMontaraoffshore oil platform exploded and released millions of litres of oil into the Timor Sea, contaminating water and killing fish in the territorial waters of Indonesia and East Timor. The oil spill of that explosion, called "Montara Timor Sea Oil Spill Disaster", actually contained black tin which mingle with dispersant chemical powder Corexit 9500 and 9572 which were very dangerous and toxic. TheMontara oil spillwas anoil and gas leak and subsequent slick that took place in the Montara oil field in theTimor Sea, off the northern coast ofWestern Australia. It is considered one of Australia's worstoil disasters.The slick was released following a blowout from the Montara wellhead platform on 21 August 2009, and continued leaking until 3 November 2009 (in total 74 days), when the leak was stopped by pumpingmudinto the well and the wellbore cemented thus "capping" the blowout.According to the investigation that conducted by Montara Oil Spill Investigation Commission, the oil spill of Montara has polluted 90.000 km2 area of Timor Sea. While Australian scientists said that 90 percent of contaminated area is in Indonesia territory. Biologists said that the effects of the Montara oil spill could be catastrophic formarine ecosystems, with claims that although it is a lightweightcrude oilspilling from the platform, it can still have toxic effects on birds,marine invertebrates,coralandmarine algae. The Wilderness Societydescribed the area as a "marine superhighway", andwhalesand endangeredflatback turtlesobserved in the area are at risk from the spill.By 3 September 2009, fishers observed sick and dying marine life, and an absence of birds in the spill area.

1. Based above cases, the oil spill could be analyzed by infrared spectroscopy. What is infrared-molecule interaction and the effect as a result of this interaction. 2. One of effects of infrared-molecule is molecule vibration. Explain why the molecule could vibrate when infrared passed of the molecule? 3. Identify and explain types of vibration as a result of the absorption of infrared by organic molecule? The vibration of organic molecule is caused by the absorption of infrared by atoms which have covalent bond in that molecule. Is there any influence of bond polarity to the absorption of infrared?4. Explain in what wavenumber the covalent bond/functional groups in an organic molecule could absorb infrared? Explain in a diagram.

Assignment 3Among the most common over the counter drugs you might find in a medicine cabinet are mild pain relievers such as ibuprofen, naproxen and acetaminophen. How many sp3 hybridized carbons does each molecule have? Explain How many sp2 hybrididized carbons does each molecule have?Explain Can you identify and spot any similarities in their structures?

Assigment 4 Explain the Lambert-Beer relationship and its application in qualitative and quantitative analysis of organic chemicals? How to determine the concentration based on the Lambert-Beer equation? Use the data in below to determine the molar extinction coefficient for the absorption band at 357 nm? Make the graph. Why is it more accurate to measure the extinction coefficientfrom a series of readings rather than a single reading? Explain.

Assignment 5

From the IR spectra in above, why are the spectra of high density polythene, dodecane, hexane similar to one another? What two features of the spectrum of hex-1-ene allow you to assign this spectrum to an alkene rather than to hexane? What is effect the transmittance or intensity of the IR spectra for the functional group and other properties of compounds? Explain. 3