Extraction of metals The History of Metals. Metals have been used by people for many thousands of years. Gold and silver‚ found as native metal‚ were used both as jewellery and as a status symbol - nothing new there. These metals were known in the Stone Age‚ but gold and silver are too soft to be used as tools. The first really useful metal to be discovered was bronze. This began the Bronze Age. Bronze was used extensively for tools and weapons in Asia and Africa from 4‚500 B.C. (6‚500 years
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As a liquid evaporates‚ it lowers the temperature of the substances around them‚ because evaporation is an endothermic process. In the graph‚ each substance has a different curve. Some lowered the temperature much more than others. This is because different substances require differing amounts of energy to evaporate. To test this‚ the temperature change from the evaporation of 4 different alcohols was measured and compared‚ along with cyclohexane. Methanol had the largest change in temperature‚ 18
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TOPIC 2 Metals The History of Metals * Uses of metals through history: * Copper Age (3200-2300 BCE) – copper and tin were most common metals‚ and were used for ornaments‚ weapons and tools. * Bronze Age (2300-700 BCE) – copper‚ tin and bronze were used for tools‚ weapons and transport. They produced bronze by heating copper and tin with charcoal. * Iron Age (1000 BCE – 1 CE) – iron steel and lead was used for tools‚ weapons and pipes. Iron is much harder than bronze.
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Transition Metals 1a) The d-orbitals of a free transition metal atom or ion are degenerate (all have the same energy.) However‚ when transition metals form coordination complexes‚ the d-orbitals of the metal interact with the electron cloud of the ligands in such a manner that the d-orbitals become non-degenerate (not all having the same energy.) The way in which the orbitals are split into different energy levels is dependent on the geometry of the complex. Crystal field theory can be used to predict
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Acid Base Titration bre’ana March 1‚ 2013 Purpose: The purpose of this experiment is to determine the concentration of a solution of NaOH by titration with a standard solution of HCl. It was also the purpose to determine the concentration of a sample of white vinegar by titration with a standard solution of NaOH. Introduction: Using the method of titration is how the experiment gets to the conclusion of the concentration of a solution. When doing this experiment‚ measurement is very important
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The purpose of the experiment was to perform an electrophilic addition reaction by the bromination of cinnamic acid. The product of this reaction is 3-Phenyl-2‚3-dibromo propionic acid‚ which is purified by recrystallization. Cinnamic acid (3-phenylprop-2-enoic acid) is an unsaturated carboxylic acid. The electron rich π cloud (see Figure 1) in the double bond of this structure is nucleophilic and can be considered a Lewis base. It can therefore be saturated by the addition of a halogen to the double
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Ammonia and Hydrochloric Acid Lab Chemistry 1 Abstract The straw should be cut shorter to 8 cm in order to make the solid ring appear in the center of the straw. We achieved our goal‚ cutting the straw caused the gases to not have to go as far‚ and meet in the middle. Background The particles in a gas are very loose and tend to move around a lot very quickly. The particles in a solid are very compact and vibrate but don’t really move very much. The particles in a liquid however are more
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Suggested time allotment: 5 to 6 hours MODULE 2 ACIDS AND BASES In Module 1‚ you identified common properties of solutions using different methods. You learned how to report the amount of the components in a given volume of solution. You also found out that not all solutions are liquid. Some of them are solids and others are gases. Towards the end of the module‚ you investigated the factors that affect how fast a solid dissolves in water. Most of the solutions you studied in Module 1
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LAB 6. ACIDS AND BASES: PH AND BUFFERS PURPOSE: To determine the pH of common acids and bases using a pH meter‚ pH paper‚ and red cabbage indicator. To test the effect of adding an acid or base to a buffer solution. SAFETY CONCERNS: Always wear safety goggles. Wash with soap and water if skin contacts acids or bases. ACIDS: An Acid is a substance that when dissolved in water will produce hydrogen ions‚ H+‚ in the solution. An acid that does not contain carbon is called an inorganic
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Corrosion of Metals Introduction Have you ever had a bike that went rusty‚ figure 1? If the paint is scratched and the rust allowed to spread‚ it is very difficult to repair the frame so it looks as good as new again. Rusting costs us millions of pounds each year‚ either through replacing things or through trying to prevent it happening in the first place. Figure 1: Bike rusting. In this booklet you learn about rusting and ways of stopping it‚ followed by a look at another metal‚ aluminium that
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