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Engineering Chemistry 14/15 Fall semester Instructor: Rama Oktavian Office Hr.: M.13-15, Tu. 13-15, W. 13-15, Th. 13-15,

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Presentation on theme: "Engineering Chemistry 14/15 Fall semester Instructor: Rama Oktavian Office Hr.: M.13-15, Tu. 13-15, W. 13-15, Th. 13-15,"— Presentation transcript:

1 Engineering Chemistry 14/15 Fall semester Instructor: Rama Oktavian Office Hr.: M.13-15, Tu , W , Th , F

2 Outlines 1. Metals and non-metals properties 2. Metals reactivity 3. Reaction with metals 4. Gas mixture

3 Metals properties The Periodic Table is divided into…. Metals

4 Metals properties and non-metals The Periodic Table is divided into….

5 Metals properties They have high melting and boiling points (except mercury) They conduct electricity and heat. They have a high density. They are shiny (lustrous). They are malleable (can be moulded) They are ductile (can be stretched)

6 Non-Metals properties Have low melting and boiling points. Are brittle. Do not conduct heat or electricity well. (except carbon)

7 Metals properties Different metals are suitable for different jobs. Gold, silver and platinum are very unreactive but very malleable - making them suitable for jewellery

8 Metals properties Copper is malleable, ductile and it conducts heat and electricity well. It is also unreactive making it suitable for holding and carrying water.

9 Metals properties Aluminium is a reactive metal, but it forms a coating of very stable aluminium oxide. This, together with its lightness and malleability gives it many uses from window frames to insulation foil.

10 Metals properties Iron ore is common and iron itself is very strong. It can be moulded into many shapes

11 Metals properties Remember: Only iron oxide is called rust. No other metal rusts! Unfortunately iron is quite brittle (for a metal) and also oxidises (rusts) easily. As it forms, iron oxide constantly flakes away exposing more of the iron underneath.

12 Metals properties Like aluminium, zinc oxidises to form a stable coating of zinc oxide which protects the iron underneath it. This is called galvanising. To prevent this happening, iron is often covered with a thin layer of zinc.

13 Metals properties Sodium, Calcium and Magnesium These three metals are all far too reactive to be much use in their pure form. They all make important compounds though.

14 Metals properties Sodium Sodium metal is so reactive it has to be kept in oil to keep it away from the oxygen in the air.. Without the oil, sodium quickly oxides into useless sodium oxide All the same, sodium is essential for both plants and animals. The commonest source of sodium is common table salt – Sodium Chloride.

15 Metals properties Calcium Calcium is less reactive than sodium, but it still oxidises too rapidly for the pure metal to have any uses. Calcium compounds, however, are very important. Calcium carbonate makes up about 10% of the earth’s surface – limestone, marble and chalk. Calcium compounds are essential for life – such as for making bones and milk.

16 Metals properties Magnesium Magnesium is less reactive then sodium or calcium. It is still too reactive to have any uses in its pure form though. Magnesium is easily obtainable from salts in sea water Amongst other things, magnesium is essential for making chlorophyll.

17 Metals reactivity Metals get more reactive as you move left in the periodic table …. so Group 1 metals are the most reactive Reactivity

18 Metals reactivity …They also get more reactive as you go down the table Reactivity

19 Metals reactivity Group 1 metals are the most reactive. then Group 2 and potassium is more reactive than sodium

20 Metals reactivity Metals all form (They do this by LOSING electrons)

21 Metals reactivity Most non- metals form (They do this by GAINING electrons)

22 Metals reactivity Groups 1 – 13 form positive ions Na + Mg 2+ Al 3+

23 Metals reactivity Group 14 elements don’t form ions This is because they have 4 electrons in their outer shell. It isn’t easier to gain 4 more or lose 4 - so they don’t do either!

24 Metals reactivity Groups 15, 16 and 17 all gain electrons to form negative ions Cl - S 2- N 3-

25 Metals reactivity Group 18 elements don’t form ions either. This is because they already have the full 8 electrons in their outer shell.

26 Metals reactivity Group 1 metals all have one electron in their outer shell. They can lose this electron to form a 1+ positive ion Fr Cs Rb K Na Li

27 Metals reactivity Fr Cs Rb K Na Li LiLi + e-e- + lithium lithium ion electron + For instance:

28 Metals reactivity Ra Ba Sr Ca Mg Be Group 2 metals have 2 electrons in their outer shell…. ….. so they form 2 + ions Ba 2+ Sr 2+ Ca 2+ Mg 2+ Be 2+ Ra 2+

29 Metals reactivity Some metals, like iron, can form 2+ or 3+ ions Fe Fe 2+ Fe e - 3 e -

30 Non-Metals properties Non-metals can form two types of ion: Monatomic ions (the ion is made from just one non-metal element) Cl - = chloride I - = iodide Br - = bromide O 2 - = oxide S 2 - = sulphide Polyatomic ions (the ion is made from more than one non-metal element) OH - = hydroxide SO = sulphate NO 3 - = nitrate CO = carbonate HCO = hydrogen carbonate

31 Non-Metals properties Non-metals can form two types of ion: Monatomic ions (the ion is made from just one non-metal element) Cl - = chloride I - = iodide Br - = bromide O 2 - = oxide S 2 - = sulphide Polyatomic ions (the ion is made from more than one non-metal element) OH - = hydroxide SO = sulphate NO 3 - = nitrate CO = carbonate HCO = hydrogen carbonate

32 Reaction with metals 1.Metals react with oxygen to from oxides. 2.Metals react with water to form hydroxides and hydrogen gas. 3.Metals react with acids to form salts and hydrogen gas.

33 Reaction with metals 1. Metals react with oxygen (O 2 ) to form oxides. sodium + oxygen  sodium oxide 4Na O2O2 +  2Na 2 O calcium+oxygen +   O2O2 calcium oxide 2Ca2CaO oxygen + +   3O 2 ironiron oxide 4Fe2Fe 2 O 3

34 Reaction with metals 2. Metals react with water to produce hydroxides and hydrogen gas. sodium + water  sodium hydroxide + hydrogen gas 2Na2H 2 O+  2NaOH + H2H2 calcium + water  calcium hydroxide + hydrogen gas Ca(OH) 2  Ca2H 2 O++H2H2 *Soluble hydroxides are called alkalis*

35 Reaction with metals 3.Metals react with acids to form salts and hydrogen gas potassium + hydrochloric acid  potassium chloride + hydrogen 2K+2HCl  2KCl+H2H2 ++ potassium + sulphuric acid  potassium sulphate + hydrogen 2KH 2 SO 4  K 2 SO 4 H2H2


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