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ENV100Y5 Lecture Notes - Lecture 6: Chemical Polarity, Reducing Atmosphere, Solar Wind

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Environment
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ENV100Y5
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Barbara Murck

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ENV100Y5 Full Course Notes
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Document Summary

Water as a molecule has a number of characteristics that make it important. The water molecules has chemical characteristics that support life. It is a polar molecule with one end being positive, and the other end being negative. It tends to facilitate the bonding of water with other chemicals. Liquid over a wide range of temperatures and such water based processes can occur across variations on the surface of the planets. Refers to how much energy do we have to put into a material to get it to change its temperature. The temperature over the land is much more variable than big bodies of water. The climate is mediated, the air above it. It"s a huge deal b/c we have lots of big bodies of water and mediates the climate. Near some big body of water, the climate is mediated by it.

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Related Questions

I want another 600 word discussion on 3-methyl-3-pentanol, here is the attached example if you need an idea. I don't want it to be the same.

"Discussion:

In this experiment, the 3-methyl-3-pentanol solution was being used in the dehydration process. The alcohol was a five carbons aliphatic hydrocarbon which one of the hydrogen atoms, H was substituted by one hydroxyl group, OH-. Due to the low melting point, the pentanol appear in liquid form at room temperature. The dehydration process of alcohol converted pentanol which the hydroxyl group, OH-was removed to become pentene. Pantene was a five carbons aliphatic hydrocarbon with a single double bond in the molecule. The solution was added with concentrated phosphoric acid in a 5-ml vial and was mixed together by swirling. The phosphoric acid was added as catalyze as such increased the rate of reaction in dehydration without affected the particular chemical reaction. The spin vain added into the solution in order to prevent over boiling of the solution.

The heating of mixture was carried out in a fractional distillation apparatus. As the mixture was heated, the alkene and water were produced as the products in the reaction. Besides, the side product and impurities of the reaction was being produced at the same time. The temperature of mixture when heating was fluctuated. During the temperature 80°C, the temperature of mixture dropped suddenly by 2°C and the temperature remained at 78°C constantly for few seconds. This was because some impurities or side products were being produced in the mixture which might had the boiling point of 78°C. The temperature of mixture dropped suddenly because the heat being was absorbed which used to break down the bonding of the side products. When the boiling point was reached, then temperature of mixture remained constant as the state of the side products are converted from liquid form to gaseous form. The temperature of mixture was increased until 107°C after all the side products were being converted.The temperature of mixture was reached to maximum at 107°C. This temperature was known as the activation temperature which the pentanol started to be dehydrated. In all the distillation process, some of the product was being lost since it washoled up in the apparatus which reduce the product yield. In order to maximize the yield, the mixture was continued to be heated at higher temperature range which more than the boiling point of pentanol. When the mixture was heated at 90°C-100°C, the water in the mixture pushed over the products into the receiving vial along the condenser. The products produced were collected in the same receiving vial.

Then, the receiving vial containing pentene, water and small amount of the impurities. Two layers liquid were presented in the receiving vial, one drop of distilled water was added into vial in order to determine the location of aqueous layer. Since the water droplet mixed with the lower layer, so the upper layer was determined as cloudy solution while the lower layer was aqueous layer. The upper cloudy layer was pentene with some impurities and water inside. The lower aqueous layer was removed and discarded. But, that is not easy to remove all the water in the receiving vial. So, anhydrous calcium chloride was being added. The purpose of adding of anhydrous calcium chloride was used to remove residual water in the organic solvent. It is known as drying agent in the organic solvent which are not dissolves in the solvent but drying the solvent. The calcium chloride clumped together with the water droplets as it solidified them. In another word, it reacted with water to form hydrates which was their preferred form when water was available. An excess drying agent should be used to ensure that all the water in solvent was removed. If the water remains in the materials collected, it could interfere with the analysis.Water had been successfully removed from the organic compound mixture, so it was very important to not reintroduce water into the mixture. The final distillation of unpurified 3-methyl-3-pentene must be done very carefully to obtain purified products. "

I need help writing a purpose for a chemistry experiment. I feel I was always do a great job, but my professor always disagrees and I’m out of ideas. The professor wants us to summarize the introduction, and summarize what you will do in each section of the experiment and state how this work will support the goal of this experiment being longer than 1/2 a page. Please, please help me right a better purpose for the experiment below. Thanks.

Experiment 9 Molecular Weight Determination of a Pure Substance Using the Ideal Gas Equation.

Introduction:

The purpose of this experiment is to determine the molecular weight of a volatile, essentially non-polar liquid. An excess amount of pure unknown volatile liquid will be placed into a flask, whose volume will also be determined. The flask will be placed into a hot water bath, whose temperature corresponds to the temperature of the gas in the flask. The liquid will evaporate, driving out the air while the excess liquid evaporates. The pressure of the gas in the flask will correspond to the atmospheric pressure. After the excess unknown liquid has been allowed to evaporate, the flask will be stoppered, cooled, and weighed to determine the grams of the unknown liquid that will be present at the temperature of the water bath as a gas. In this experiment the ideal gas equation will be used PV = nRT = (g/M)RT where R = 0.0821 L*atm/mol*K, T = temperature in K, P = pressure in atm, V = volume in liters, n = moles of gas, g = grams of gas, and M = molecular weight of gas (in units of g/mole). Solving for the molecular weight, M: M = gRT/ PV.

If the molecular weight of a gas is to be determined, the m, T, P, and V must be determined experimentally in the lab. Even though the ideal gas equation is only an approximation of the behavior of gases, molecular weights can still be obtained within 5% of the correct values, as long as volatile non-polar compounds or compounds with only slight amount of polarity are used. For example, C, H, compounds as CH4 are essentially non-polar, whereas compounds as H2O are highly polar. Hence, the ideal gas equation would not be a good approximation for describing the behavior of gaseous water.

Procedure:

At the very beginning of the period get a one-liter beaker. Put about 800 mL (your instructor will tell you the exact amount needed) of tap water into the one-liter beaker. Put the one-liter beaker with water onto the hot plate. Set the heat setting of the hot plate to the maximum value. The water in the beaker should be boiling very lightly prior to doing the actual experiment. Therefore, after the water starts boiling in the hot water bath, it may be necessary to cut the heat setting back from highest value. This will take some time. While the water is heating, get the rest of the things needed for this experiment. The setup is shown in figure 1. Record the barometric pressure (in torr to one decimal place). Obtain the rest of the setup consisting of a 250 ml flask, properly prepared rubber stopper with glass tube and aluminum foil, a no-hole rubber stopper, thermometer, and glass stirring rod.

Make sure the 250 mL Florence (or Erlenmeyer) flask is dried (if it is not dry, rinse with 5 mL of acetone, pour off the acetone into the waste bottle in the hood, and then clamp the 250 mL Florence flask onto the ring stand in the inverted position to allow the last traces of acetone to drain out and evaporate. Place the dry no-hole stopper on the flask and weight the flask with the rubber stopper on the balance to 3 decimal places. Record this weight for the weight of the flask plus rubber stopper and moist air. Place 5 mL with a graduated cylinder of unknown liquid into the flask. Place the one-hole rubber stopper, with tube and aluminum foil in the flask. This one-hole stopper, which contains a glass tube that sticks out on the top by 3 mm and is flush with the bottom of the stopper, is covered with aluminum foil with a hole punched into the bottom where the glass tube is. This one-hole rubber stopper is already prepared for you. Push it down firmly into the flask. Remove it. Do this 2-3 times to smooth out the aluminum foil so that the stopper will go down into the flask as much as possible. Then push the stopper down so that it fits snugly but not too tightly to allow it to be removed while the flask is hot. Clamp the flask about the top lip of the Florence flask. That is, the center of the clamp goes about the rim of the flask. Push the flask as far down into the water bath as possible while holding the end of the clamp with your other hand. It is important to be sure that the water in the water bath is always at least 5 mm above there the bottom of the stopper is in the flask. More water may have to be added as some of the water evaporates during the duration of this experiment. (A beaker with hot water (extra) should be present in the hood. One or two of these beakers of hot water should be enough for everyone.) If the water level is not kept to its proper height, the liquid will condense in the upper part of the flask and the excess liquid will never be removed. Be sure that the aluminum foil on top makes a protective wind breaker for the short glass tube sticking out of the rubber stopper so that condensation does not occur there also. As the liquid evaporates from the flask, mix the water in the water bath occasionally and check to see that the temperature remains constant. Record the temperature value of the water bath as the temperature of the gas in the flask for the temperature of the gas would have equilibrated to the temperature of the water bath. After all the liquid has evaporated (takes 2-5 mins for the liquid to evaporate.) from the flask (check carefully that all of the liquid has evaporated-since observing when all the liquid has been evaporated maybe difficult, you should carefully shake slightly the clamp holding the Florence flask to observe the movement of the unknown liquid and when it has disappeared) and none is condensed on the surface walls; (if condensation occurs, be sure all precautions mentioned above are taken) then (these next several steps are to be done quick) remove the rubber stopper with the glass tubing and aluminum foil without excessive shaking. There could be a condensed liquid droplet or two in the glass tube that is not visible. The droplets could drop back into the flask and cause a false high reading for the measured weight of gas in the flask. Immediately replace the rubber stopper (with the glass tube and aluminum foil) with the no-hole stopper, which was used when the flask was originally weighed. This step must be performed quickly to prevent the unknown gas vapors from escaping and being replaced by moist air. Place the no-hole rubber stopper in the Florence flask firmly. Remove the flask from the bath and again check to be sure that the no-hole rubber stopper is firmly in place. Cool the flask by running tap water over the flask for 30-60 seconds. If the stopper is not fitted firmly, air will enter the flask as the liquid inside the flask condenses. As the gas cools and changes to the liquid state, a partial vacuum is created inside the flask. Hence, air will enter the flask if the rubber stopper is not fitted firmly. Completely dry the flask and weigh it on the balance to three decimal places. Record the weight of flask plus stopper and unknown gas.

Repeat this entire procedure a second time and record the date. After, second trial, completely fill the flask with distilled water. Place the no-hole rubber stopper in the flask allowing the excess water to overflow. Wipe the outside completely dry. Then measure the volume of the water in the flask by pouring water into a graduated cylinder. Record this volume.

I need help on this microbiology question:

Contrary to our favorite science fiction books and movies, the chances of us finding another planet with a civilization comparable to, or even more advanced than our own, seems highly unlikely. But, through your work as a microbiologist at NASA, you have been able to help change our views as to what forms of life we should be looking for on planets in our solar system and around neighboring stars. Instead of radio signals or errant transmissions, we have begun looking for planets that have environments similar to those capable of sustaining life as we know it here on Earth. To determine what we could find out there, you have begun studying different unique and atypical environments found here on Earth. Although the harsh conditions of hot springs or undersea sulfur vents seem incompatible with most forms of life, organisms known collectively as "extremophiles" have still managed to survive and adapt to these extreme conditions. You believe extremophiles may help you gain insight into the potential metabolic requirements, processes, and challenges of extraterrestrial life. Thus far in your search, you have identified some prokaryotic cells that have evolved to survive in the extreme conditions of sulfur vents on the sea floor. These vents are found at great depths, where the crushing pressure and lack of light and oxygen are prohibitive to many forms of life. Bacteria that are not considered extremophiles reside in most ecological niches on this planet. There are some common criteria for the environment that would sustain these bacteria. Availability of water, pH that lies between 5 and 9, temperatures that will remain steady and below boiling; these are some of the characteristics that bacteria will require in their environment if they are to succeed. But in the environment of the ocean floor vents, not only is the pH of the water very low, but also the water temperature is unusually high due to the geologic activity that fuels the vents. Organisms that are adapted to such harsh conditions have necessarily evolved enzymes able to function beyond average optima, as well as a chemosynthetic metabolism capable of using vent organic and inorganic compounds as energy sources.

Part A - Comparable Earth Environments to Be Found on Another Planet

You identify the prokaryotic cells you've found as a species of bacteria. These bacteria appear to be living off of nutrients and sulfur compounds released from the vents on the sea floor. Over time, the bacteria must have evolved extreme metabolic and enzymatic capabilities to allow them to tolerate and even benefit from the extreme depths, the lack of oxygen, the low pH of the surrounding waters, high temperatures due to volcanic releases, and the unique nutrient source of the vents.

Choose the characteristics and their impact on enzyme activity that are not correct from the following statements. (more than one may be chosen)

Archaea are able to tolerate highly acidic pH environments and have proteins that will not denature in the low-pH environments that the bacteria are found in.
Archaea are able to colonize water that is at or above the boiling temperature due to high levels of disulfide bridges that maintain the three-dimensional structure of the enzyme.
Archaea are only able to survive exceedingly well at high temperatures due to the amount of activation energy required by their enzymes.
Archaea are able to grow in extremely shady or low-light conditions that allow for optimal enzyme activity.