A combination of research and laboratory experimenting were used to determine which of the four suggested compounds was most suitable for a ceramic pottery glaze. The melting and boiling points of the compounds were researched, and the color of crystal and solution, conductivity, and solubility in water and ethanol were determined empirically. Only one of the four provided compounds had a favorable result when tested against all of the criteria. Based on the final data, the chemical recommended for use in this glaze is sodium chloride.
A pottery company has requested that the Chemical Magicians find a suitable glaze for their ceramic pottery. The requested glaze should have some ideal properties. Firstly, it should be white when solid and clear when dissolved. Secondly, it should dissolve in water but not alcohol (ethanol). It should also be electrically conductive in aqueous solution. Finally, it should have a fairly highly melting point used for firing in the kiln.
Four compounds have been suggested. They are sucrose (C12H22O11), sodium chloride (NaCl), sodium carbonate (Na2CO3), and salicylic acid (C6H4(OH)COOH). The compounds will be researched to find out their properties, and tests in the lab will be carried out to confirm and elucidate these properties further. All properties with the exception of boiling point will be tested, as boiling point is the one property that is difficult to determine accurately in the lab.
[...] Finally, the delicious nature of the glaze may be problematic for one with small children, who may be inclined to constantly lick at the glazed ceramic object. In short, sucrose is not recommended as a compound to use for this glaze Sodium Chloride Sodium chloride is probably the most suitable candidate for this glaze. Its melting point, at 801°C3,7, is, out of the four, the lowest melting point that is still within the range of acceptable temperatures. Its boiling point, at 1413°C3,7, is high enough to withstand the high end of temperatures found in a typical kiln. [...]
[...] Again, hopefully no ingestion of anything will be occurring in the lab, though it is worth noting that if the glaze is used on dishes and the like, problems may occur. Finally, it is also classified as a reproductive system toxin. If possible, wear gloves and avoid exposure as much as possible Procedure Materials 4 100mL beakers 400 mL of distilled water Conductivity test 100mL of ethanol 39.23 g sucrose 10.84 g sodium chloride 15.60 g sodium carbonate 18.81 g salicylic acid Weigh boat Stirring rod Scoopula Procedure 1. [...]
[...] This problem is not a strong reason not to use sodium chloride, however, as the carcinogenic potential is incredibly low and it displays all the desirable properties, so it is our recommended compound for use in this glaze Sodium Carbonate Sodium carbonate is not quite as desirable as sodium chloride for this glaze. All but one of the desired properties is completely or nearly completely satisfied. Its melting point is 851°C4,8, and it decomposes at roughly 1600°C4,8, an acceptable temperature range though the lower bound is potentially a bit high. [...]
[...] The Chemical Magicians do not recommend salicylic acid for use in this glaze Overall Compound Crystal Solution Water Ethanol Conductive? M. P. Recommend? color color soluble? soluble? beige chloride carbonate acid solvatio n 5. Conclusions Overall, sodium chloride stands as the Chemical Magicians' best recommendation for the compound to be used in the glaze. It meets all the requirements, is nearly non-toxic, and is extremely economical. However, we would like to recommend that a more traditional, unreactive, and also quite economical glaze composed of silica10 be used instead if possible, since sodium chloride dissolves in water and is reactive with some metals3,7. [...]
[...] can lead to problems. Toxicity may be a problem, not in the lab, but in exposure to the general public. Finally, a consideration is how reactive each compound is, as one does not know what is being put into each container Sucrose Sucrose, C12H22O11, otherwise known as table sugar, is a white crystalline disaccharide, solid at room temperature2,6, formed by the dehydration reaction of a molecule of glucose and a molecule of fructose. It is a covalent solid, held together by a 1,2 glycosidic linkage11. [...]
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