Abstract This paper discusses how magnesium chloride has become the de-icer of choice in snowy regions such as Colorado and how supporters of the product claim that magnesium chloride is an environmentally safer option for de-icing than some of its predecessors, namely, sodium chloride. It examines how the use of magnesium chloride in liquid and modified cold-pressed form has been shown to be highly effective as a tool for de-icing in Colorado. It also looks at how supporters of the use of magnesium chloride in Colorado have stated that the de-icer has proven beneficial to the environment, while others claim the use of magnesium chloride has been shown to possibly increase electrical outages and pole fires, as well as corrosion.
From the Paper "Another environmental issue facing Coloradoans resulting from the use of magnesium chloride is corrosion. The use of sodium chloride or rock salt in the past presented a much greater problem in this respect. Magnesium chloride however, is also by nature corrosive; however proponents of its use point out those chemical agents are added to it to minimize the corrosive effects (Pavek, 2002). Highway departments in the state of Colorado have noticed that the use of magnesium chloride as a de-icer has reduced much of the major corrosion on trucks and equipment, as well as steel enforced bridges compared to sodium chloride (Pavek, 2002). However, some reports are also indicating that aluminum components and electrical components in their vehicles are actually showing increased evidence of corrosion at a more rapid rate (Pavek, 2002)."
A paper analyzing the physical and chemical properties of the lead (II) and lead (IV) halide compounds. Comparisons between compounds and applications are also discussed.
Abstract After a brief historical introduction to lead compounds, it explains what +2 and +4 cations are and examines their uses. The physical and chemical properties of the lead (II) halides are also discussed, with mention of "mixed" halides (e.g., PbFCl).
Outline
An Introduction to Lead
General Lead Dihalide Trends
Mixed Lead Halides
Lead Chloride Lead Bromide
Lead Iodide
Lead Fluoride
Lead Tetrahalides
Lead Tetrafluoride
Lead Tetrachloride
Possible Lead Halide Application
From the Paper "Lead, located at the bottom of group IVA on the periodic table is well known for being a massive (atomic mass is 207.2 amu) and dense element. The density characteristics associated with lead arise from its rather compact structure despite its large size. This occurs in accordance to the periodic trend that atom size decreases as one moves left to right across a period. This trend, in conjunction with the massive properties found among the period six elements, accounts for the elements ranging from osmium to lead in that row being the densest (osmium does have the largest density) known to exist."
Abstract The paper explains that magnesium chloride (MgCl) plays a role in wound closure of flatworms, so it was hypothesised that the higher concentrations of MgCl would decelerate the healing process, preventing the two planaria head halves from reattaching and thereby leading to the generation of two complete heads. The paper discusses the results and relates the purpose of the experiment that is to help people recover lost limbs and regenerate nervous tissue.
Outline:
Materials & Methods
Results
Discussion
From the Paper "Planaria are free-living flatworms that can be found in marine, aquatic, and terrestrial environments [1]. The planarian is a member of the phylum Platyhelminthes, and class Turbelleria which is known for having simple organ systems. It consists of a small brain, perceptual organs and digestive system that comprises of a mouth, pharynx, and an intestine [2]. Planaria are known for having a highly robust regeneration system [3]. When part of its body is transected, each piece (as little as 50mm3) of that part has the ability to regenerate itself [4,5]."
Abstract This paper examines an experiment in which the kinetics of a nucleophilic substitution were observed, more specifically, the hydrolysis of t-butyl chloride. Furthermore, the paper discusses how the experiment confirms the kinetic order of the reaction. The materials and methods that were used are also discussed, as well as results of the experiment, which are shown in a table.
Table of Contents:
Introduction
Materials and Methods
Results
Discussion
Appendix
From the Paper "Sources of errors in this experiment are mainly normal human error, such as slight inaccuracies when using the pipettes (either when taking up or emptying the liquids). If there was also inconsistency (i.e. it was inaccurate for a different reason each time), then this could have a significant impact on the results. Also, deciding when the colour had completely changed (and thus, the reaction had gone to completion) depended on the lighting and the angle at which each experimenter stood from each flask. In terms of modifying the temperature, there was always a delay between attaining the target temperature and the thermometer reading, since the heat could not be perfectly spread out in the flask and it took time for the temperature to stabilize."
A review of an experiment that determined the reagent that would be limiting and the mass of the precipitate that would be formed in a chemical reaction.
Abstract The paper predicts the mass of precipitate that would be produced by the reaction of 2.00 g of strontium chloride with 2.00 g of copper (II) sulfate pentahydrate in 75 mL of water. The paper lists the materials utilized in this experiment, the procedure and the data collected. The paper provides the calculations used and shows how the prediction that was made turned out to be accurate.
From the Paper "The actual mass of the precipitate is 0.29 g. However, this is not entirely accurate. When removing the filter paper from the funnel the paper ripped, causing some of the precipitate to fall off onto the paper towel below. As a result, the observations are not entirely accurate because the mass of the filter paper and the precipitate should be higher. This also caused the calculation of the actual mass of the precipitate to be slightly lower than it should be. This was a human source of error, as it cannot be fixed after the error was made."
Tags: strontium, chloride, copper, (II), sulfate, pentahydrate, filter, paper
From the Paper "The unknown sample L03-02 was determined for the anions fluoride, chloride, nitrite, nitrate and bromide. The anions were determined using HPLC. The type of HPLC used was ion-exchange chromatography. The sensitivity of ion-exchange chromatography has made precise measurements at the ppm level for many inorganic anions commonplace3. Ion-exchange chromatography was chosen as the method for this lab because of its' sensitivity and its' ability to determine as many as 10 inorganic ions in a single measurement at better than an ion per minute3."
From the Paper "Compared to most other materials, plastics have been introduced relatively recently. In fact, many of the major developments in plastics technology have occurred over the last 50 years. One plastic that currently finds widespread application in the construction industry is polyvinyl chloride (PVC). Although PVC has been around for over 100 years, it wasn't developed commercially until about the 1930s. The pure resin consists of a linear polymer. The compound's chlorine atoms cause considerable inter-chain attraction. Hence, in its pure state, the material is hard and rigid. With modifying agents, however, PVC can be softened to produce an entire array of flexible products. Indeed, the substance may be the most versatile of the plastics. PVC is currently found in cable..."
From the Paper "In hospitals in the United States, over one million medication errors occur each year, resulting in 120,000 deaths.
The problem is so prevalent that the American Medical Association has launched a Medication Error Reduction Initiative (Voelker, 1996, pp. 1537-1538). The Joint Commission on Accreditation of Healthcare Organizations has reviewed more than 200 sentinel events and found that the most common category of such events was medication errors. Of these, the most frequently implicated drug was potassium chloride according to the Sentinel Event Alert (1998). This paper will look at ways in which hospitals are responding to reduce these mistakes.
A recent study of two hospitals found four major causes for medication errors (Davis, Leape, Nightingale, Weart, & Galper, 1997, p. 30). The four causes were: lack of adequate knowledge.."
Abstract This paper looks at hydrates, and how to calculate their water content. It calculates the water content for copper sulfate hydrate and magnesium chloride hydrate.
From the Paper " A hydrate is a type of salt containing water within its crystal structure. In this experiment the mass percent of water in a hydrate was determined by heating a sample of the hydrate to remove the water and then comparing the mass of the sample before and after heating. From this the empirical formula of the hydrated salt was determined. This was carried out for copper sulfate hydrate CuSO XH O and for magnesium chloride hydrate MgCl XH O. A crucible was weighed to the..."
Abstract This is a report on an experiment in chemistry on the law of definite proportions. It looks at the decomposition of potassium chlorate to potassium chloride with heating.
From the Paper "The law of definite proportion states that different samples of a pure compound always contain the same elements in the same proportions by mass. For example, sodium chloride always contains sodium and chlorine by mass. In this experiment a sample of potassium chlorate was thermally decomposed to determine the mass percent of oxygen in the compound. A crucible containing g MnO catalyst was weighed and g KClO was added and the crucible and contents reweighed. A thermometer was placed in the crucible and..."
Abstract The paper describes sodium bicarbonate as a non-hazardous substance found in a number of household and industrial applications. The paper outlines the health and safety issues and medical uses of this compound.
Outline:
Health and Safety Issues
Medical Uses
From the Paper "Sodium bicarbonate is, in general, a non-hazardous substance found in a number of household and industrial applications. The formula for Sodium bicarbonate is NaHCO3. Its molecular weight is 81.01 (1). It is also known by the common names Sodium hydrogen carbonate; sodium acid carbonate; baking soda; and bicarbonate of soda (1). It appears as a white, solid crystalline form, but sometimes as a fine, white powder (1). It can be purchased from a number of scientific and general population sources."
Abstract This paper describes an experiment designed to determine the fate of Planaria that had been cut in half, while immersed in varying concentrations of MgCl, as Magnesium has been shown to relax smooth muscles, inhibiting wound closure. The experiment had fatal results for the Planaria that were in the two highest concentrations of MgCl. It should also be noted that the experiment had to be halted after just five days, due to another student mishandling and spilling the Planaria. The data gathered leading up to the halt of the experiment showed that Planaria which are in the highest concentrations (provided that the concentration is not high enough to be fatal) of MgCl will have the slowest rate of regeneration and wound closure.
From the Paper "The class of Turbellaria contains the phylum Platyhelminthes, and the family Planariidae to which Planaria belong to. Planaria are free-living flat worms that can be found in marine, aquatic, and terrestrial environments. The planarian has very simple organ systems. It consists of a small brain, perceptual organs and digestive system that comprises of a mouth, pharynx, and an intestine (Pitt-Bradford, 2002). However, it is a planarian's morphogenesis that can be mysterious and is of interest. Planaria have highly robust regeneration systems with the ability to re-grow lost body parts (Brooks and Rodney, 1999). When part of its body is excised, each piece of the part has the ability to regenerate itself (Reddien and Alvarado, 2004). During regeneration, muscle contractions in the Planaria close the wound, followed by the spreading of epithelial cells. Regeneration in planarians depends on a population of adult stem cells called neoblasts that have the potential to turn into any type of planarian cell (Reddien et al, 2005). By studying this process, one can expand their scientific knowledge and perhaps develop ways of helping out other people and animals that have lost their limbs by finding a way of having their body regenerate the missing appendage back."
Abstract This paper examines the effects of dehydration by looking at why water is essential to health maintenance, the functions of water in the body and what happens to the body when it does not get the water it needs. It further compares and contrasts how different electrolytes including sodium, potassium and chloride function in the body. In addition, the paper examines the effects of alcohol and caffeine on hydration levels in the body and what steps people can take to ensure they do not become dehydrated.
Outline:
Introduction
Water and the Body
Water's Role
The Body's Shifting Need For Water
Salt and Water for Proper Hydration
Signs of Dehydration
Effects of Alcohol on Body's Hydration
Summary & Conclusion
From the Paper "As the body ages and particularly in the twenties when there is a decrease in growth hormone production the body's perception of thirst decreases. Growth hormones "regulate water in conjunction with histamine." (Klotter, 2001) Aging of the body results in a lesser awareness of thirst and resulting is a lessening in water consumption and the water content "within cell decreases so that cellular water can be redistributed to the brain and other vital functions" of the body. When the body does not intake enough water the body's neurotransmitter "histamine is activated" which in turn "activates prostaglandins, kinins, and vasopressin, in an effort to redistribute water according to priority." (Klotter, 2001) When the body doesn't receive enough water, resulting can be problems that include damage to the DNA as well as "reduced efficiency of DNA repair system, immune suppression, and irregular protein production in cells, which encourages cancer cell formation." (Klotter, 2001) "
