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BACKGROUND INFORMATION The following information is all the background information from my experiment Phosphoric acid:- Phosphoric acid can exist as a crystal or clear liquid. It is an oily, thick, colourless and odorless liquid, or a thick, colourless, unstable crystalline solid. Phosphoric acid is used in the manufacturing of phosphates; such as salts, soaps and detergents; fertilizers; yeast; fire control agents, opal glass; electric lights; dental cements; waxes and polishes; gelatins, ethybenzene, propylene, and cumene; and soft drinks. It is also used as an acid catalyst, soil stabilizer, and a antioxidant in food. Chemical properties:- Phosphoric acid is incompatible with strong caustics and most metals. It readily with metals to form flammable hydrogen gas. The liquid can be solidified at a temperature below 21 degrees Celsius. The acid is corrosive to ferrous metal and alloys. It is soluble in alcohol and hot water. It can form three series of salts; primary phosphates, dibasic phosphates, and tribasic phosphates. It is deliquescent and hydroscopic. It is a chelating agent. Also phosphoric acid has a low vapour pressure at room temperature. Zinc:- Atomic mass:- 65.39 amu. Melting point:- 419.58 degrees Celsius. Boiling point:- 907 degrees Celsius. No of protons/electrons:- 30. No. of neutrons:- 35. Crystal structure:- hexgonal. Density@ 293K:- 7133 g/cm cubed. Date of discovery:- 1746. Discoverer:- Andreas Marggraf. Name of origin:- from the German word zin (meaning tin). Obtained From:- zinc blende, calamine. Properties:- Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures but malleable at 100 to 150 degrees Celsius. Zinc is a fair conductor of electricity, and burns in air at high red heat with evoulution of white clouds of the oxide. It has unusual electrical, thermal, optical and solid-state properties that has not been fully investigated. Uses:- The metal is employed to form numerous alloys with other metals. Brass, nickel, silver, typewriter metal, commericial bronze, spring bronze, German silver, soft solder, and aluminium solder are some of the more important alloys. Chemical Reactions:- four things that happen when a chemical reaction occurs. 1. Colour changes:- Different combs of molecules reflect light differently. A colour change indicates a chemical in the molecules. 2. Heat content changes:- In all chemical reactions, the heat content of the reactants and the content of the products is never the same. Sometimes the difference is great and can be easily detected; at other times the difference is slight and is more difficult to detect. 3. A gas is produced:- Whenever a gaseous product forms in a liquid solution, bubbles can be seen. A colourless gas produced in a reaction of solids is much harder to detect. 4. A precipitate forms:- Precipitates are insoluble products formed by a reaction taking place in a liquid solution. This insoluble product will eventually settle to the bottom, but might immediately appear by turning the clear solution cloudy. How does a battery function:- A battery has 2 two terminals, one positive and the other negative. Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as they can battery very quickly. Inside the battery itself, a chemical reaction produces the electrons. The speed of electrons production by this chemical reaction controls how many electrons can flow between the terminals. Electrons flow from the battery into a wire, and must travel from the negative to the positive terminal for the chemical reaction to take place.
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