1. Types of Chemical Change http://mrged.flexinet.com.au

2. You already know about, 1.The two main types of chemical bonding 2. Writing chemical formulas (formulae)

3. This week we will find out about; 1.Synthesis Reactions 2. Decomposition reactions 3. Single replacement reactions 4. Double replacement reactions

4. The Periodic Table

5. Types of chemical bonding. Revision

6. Ionic Bonding This type of bonding will occur when a metal reacts with a non -metal It always involves a complete transfer of electrons  It always produces IONS (charged particles)

7. View animation at http://mrged.flexinet.com.au 1 Na reacts with 1 Cl Formula = NaCl

8. Covalent Bonding This type of bonding will occur when a non- metal reacts with a non - metal Here both atoms will share electrons  It always produces molecules (particles with no charge)

9. In this section we will find out how to write chemical FORMULAE

10. Rules leading to correct formula Please copy into your exercise books 1. Positive ions (cations) can join to negative ions (anions) 2. Positive ions usually form the first part of the name (99% cases) 3. If the formula is correct there is no overall charge 4. If you have more than one polyatomic ion it is placed inside brackets

11. Essential training ions Positive ions (Cations) Negative ions (Anions) + 1 - 1 +2 - 2 +3 - 3 sodium Na potassium K hydrogen H lithium Li silver Ag fluoride F chloride Cl bromide Br hydroxide OH nitrate NO3 hydrogencarbonate HCO3 magnesium Mg calcium Ca barium Ba zinc Zn iron(11) Fe copper Cu carbonate CO3 oxide O sulphide S sulphate SO4 sulphite SO3 chromate CrO4 aluminium Al chromium Cr iron(111) Fe nitride N phosphate PO4 ammonium NH4

12. Chemical Formulae 1. CHARGES IONS NUMBERS FORMULA sodium fluoride Na F

13. Chemical Formulae 2. CHARGES IONS NUMBERS FORMULA magnesium fluoride Mg F

14. Chemical Formulae 3. CHARGES IONS NUMBERS FORMULA silver hydroxide Ag OH

15. Chemical Formulae 4. CHARGES IONS NUMBERS FORMULA calcium nitrate Ca NO3

16. Chemical Formulae 5. CHARGES IONS NUMBERS FORMULA ammonium carbonate NH4 CO3

17. Chemical Formulae 6. CHARGES IONS NUMBERS FORMULA aluminium bromide Al Br

18. Chemical Formulae 7. CHARGES IONS NUMBERS FORMULA chromium sulphide Cr S

19. Chemical Formulae 8. CHARGES IONS NUMBERS FORMULA BLANK ITEM

20. Try these: 1. lithium sulphite 2. barium hydroxide 3. copper carbonate 4. hydrogen sulphide 5. magnesium nitride 6. ammonium bromide 7. aluminium oxide.

21. In chemistry there are millions of chemical reactions. But most reactions can be classified as one of four types of reactions: Synthesis: A + B -> AB Decomposition: AB -> A + B Single Replacement: A + BC -> AC + B Double Replacement: AB + CD -> AD + CB

22. Synthesis (Composition) In a synthesis reaction (also known as a composition reaction), two substances combine to form a larger substance. C OO + C OO

23. Here are 3 synthesis reactions: Hydrogen + oxygen yields water 2H 2 + O 2 -> 2H 2 O Magnesium + nitrogen yields magnesium nitride 3Mg + N 2 -> Mg 3 N 2 Iron + sulphur yields iron(II) sulphide Fe + S -> FeS

24. Decomposition In a decomposition reaction, a larger substance breaks apart and forms two or more simpler substances.

25. The first thing you may notice about a decomposition reaction is that it is the complete opposite of a synthesis reaction. In fact many synthesis reactions can be reversed into a decomposition reaction. When you burn hydrogen gas, the hydrogen combines with oxygen to produce water. 2H 2 + O 2 -> 2H 2 O With an electrical current, water can be decomposed into hydrogen and oxygen gas. 2H 2 O -> 2H 2 + O 2

27. Some examples of decomposition Heat copper carbonate and it will decompose (Refer to flash animation.swf) CuCO 3 -> CuO + CO 2 (Most carbonates decompose producing the oxide and carbon dioxide) Heat lead(11) hydroxide and it will decompose Pb(OH) 2 -> PbO + H 2 O

28. FORMALUMBRO.MOV THERMITE.MOV REDUCTIONCUO.MOV FormWater.MOV NitrogTriiodide.MOV PrecipitaReact.MOV 6x Quicktime mov files

29. 1. Watch all 12 mov files (available on SET drive) 2. Classify each as either, synthesis, decompostion, single of double replacement reactions 3. Write a correct chemical equation for each! Some may require some research TRY THESE:

30. Single Replacement In a single replacement reaction, a more active element replaces a less active element in a compound. more reactive less reactive

31. Single Replacement Here Mg is more reactive than Pb

32. Single Replacement No surprise! fluorine is more reactive than chlorine If fluorine gas is bubbled through a solution of potassium chloride, the fluorine will replace the chlorine. 2KCl + F --> 2KF + Cl This reaction can be represented as follows;

33. Please note this PPT may be updated over the weekend Mr G