THEME 2

Alloys

The History of Metals

2. Uses of metals through history:

* Copper mineral Age (3200-2300 BCE) – copper and tin had been most common alloys, and had been used for ornaments, weapons and tools. 5. Bronze Grow older (2300-700 BCE) – copper, tin and bronze had been used for tools, weapons and transport. They produced bronze by heating system copper and tin with charcoal. 2. Iron Age (1000 BCE – 1 CE) – iron stainlesss steel and business lead was used for tools, weaponry and piping. Iron is a lot harder than bronze. 2. Modern Age (1 CE – Present) – main alloys are flat iron, aluminium and steel, which are used for water lines, buildings, travel and electric cables. This can be the age where technology of iron and steel improved. Around the 1880's, there was a tremendous move towards new alloys and precious metals, including tungsten steel (cutting tools), manganese steels (railway lines and digging tools), silicon, chromium, nickel and vanadium. 5. Uses of metals

* Flat iron and metallic – railways, bridges, roof, motor car bodies, ships, fire hydrants, domestic home appliances, heavy professional machinery, water lines, nails. 2. Aluminium – buildings, aeroplanes, car parts, home pots and pans, wrapping foil. * Copper – electrical wiring, pipes and plumbing accessories, jewellery. 5. Zinc – protective chemicals, galvanizing golf irons

* Lead – car batteries, domestic plumbing, solder.

5. An metal is a homogeneous mixture of a metal with one or more other elements Alloy| Properties| Uses

Stainless (10-20% chromium, 5-20% dime, iron)| * Hard 5. Resists corrosion| food processing machinery, kitchen sinks and home appliances, cutlery, medical and oral instruments, razor blade blades| Brass(50-60% copper with zinc)| 5. Lustrous rare metal appearance 5. Hard 2. Easily machined| Plumbing accessories, musical tools, decorations| Bronze(80-90% copper and tin)| 2. Hard 5. Resists corrosion * Very easily cast| Boats propellers, casting statues| Duralumin(95% aluminium, 4% copper and 1% manganese)| * Low density 2. Very strong| Aircraft parts, racing bicycles| Solder(30-60% tin with lead)| * Low melting stage * Sticks firmly to other metals when molten| Joining metals together, particularly in plumbing and electronics| 2. A large amount of strength input is necessary for the extraction of metals using their ores, since energy is needed to: * My very own the ore

* Purify or concentrate the ore

* Conserve the high temperatures necessary to make the extraction reactions 2. Purify the raw material or to form it in to useful alloys Reactions of Metals

2. Reaction with oxygen (oxidation, corrosion)

* Almost all metals besides silver, american platinum eagle and rare metal form oxides * It is the least and slowest response, and only occurs with the strong reactive alloys * Biggest observation can be rust or perhaps loss of the shiny lustrous appearance * 2Mg(s) + O2(g) →2MgO(s)

* 4Fe(s) + O2(g) → 2Fe2O3(g)

* Effect with acidity

5. All metals except water piping, silver, rare metal and american platinum eagle react with acid to create hydrogen gas * Is it doesn't fastest and the most obvious response, occurring with most alloys * Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

* 2Fe(s) + 6HNO3(aq) → 2Fe(NO3)2(aq) + 3H2(g)

* Response with water

* In the event that water, varieties metal hydroxide and hydrogen gas

5. If steam, forms steel oxide and hydrogen gas

* 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

* Ca(s) + H2O(g) → CaO(aq) + H2(g)

* Based on how reactive metals are with these chemicals allows us to consider an activity group of most to least reactive metals. 2. K Na Li Handbag Ca Magnesium Al Zn Fe Sn Pb Cu Ag Rehabilitation Au

* The reaction of metals with acids needs the transfer of electrons. * Intended for the reaction of aluminium with dilute acid solution, the 50 percent reactions are: * Approach → Al3+ + 3e-

* 2H+ + 2e- → H2

* To balance these types of equations, there should be equal sum of electrons in the two equations....

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