1. PDP Chemistry Chemical reactions

2. Topic 1: Chemical reactions Atoms Chemical reactions are atoms rearranging Equations Signs of a chemical reaction Balancing chemical equations Types of chemical reaction Measuring chemical quantities

3. How are you going to take notes?

4. Atoms What is everything made of?

5. In Six Easy Pieces, Richard Feynman said: If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms.

6. (Almost) everything is made of atoms Images:http://en.wikipedia.org/wiki/Rock_(geology), http://en.wikipedia.org/wiki/Tree, http://en.wikipedia.org/wiki/Human, http://en.wikipedia.org/wiki/Star

7. How big is an atom? about 10 -10 m  if an atom was the size of a grain of sand, humans would be the size of a planet. Image: http://en.wikipedia.org/wiki/Earth, http://en.wikipedia.org/wiki/Sandhttp://en.wikipedia.org/wiki/Earth

8. The periodic table lists the elements in order of atomic number Image: http://en.wikipedia.org/wiki/File:Periodic_table.svg

9. Chemistry is atoms rearranging

10. Describing chemical changes Liquid oxygen and liquid hydrogen fuel Image: http://en.wikipedia.org/wiki/Saturn_Vhttp://en.wikipedia.org/wiki/Saturn_V Launch of Apollo 11 Launch of Apollo 11 (from 6 min)

11. Some changes are only changes of phase, not chemical changes Image: https://commons.wikimedia.org/wiki/Categor y:States_of_aggregation

12. Atoms are rearranged to make new substances in chemical reactions. Hydrogen + Oxygen  Water 2 H2 + O2  2 H2O Image: http://labspace.open.ac.uk/mod/resource/view.php?id=438900

13. Equations describe chemical reactions

14. reactants  products Hydrogen + Oxygen  Water 2 H2 + O2  2 H2O

15. State symbols (s) (l) (g) (aq)

16. Signs of a chemical change How do we know a chemical reaction is occurring?

17. Sodium reacts with water

18. Dilute sulphuric acid reacts with potassium hydroxide solution

19. Lead nitrate solution reacts with potassium iodide solution

20. Magnesium and hydrochloric acid

21. Signs of a chemical change

22. Elements, compounds, atoms, molecules, ions

23. Molecules  Build a molecule PhET http://phet.colorado.edu/en/simulation/build-a-molecule http://phet.colorado.edu/en/simulation/build-a-molecule  States of matter: Basics http://phet.colorado.edu/en/simulation/states-of-matter- basics http://phet.colorado.edu/en/simulation/states-of-matter- basics

24. What is an atom?

25. Symbols and formulae

26. Ethane, C 2 H 6

27. Naming compounds

28. Ionic compounds (usually metal + non-metal)  NaCl  KI  LiF  CaCl2  MgSO4  CaCO3  H2SO4  H2O

29. Common Anions Common NameFormulaAlternative name Simple Anions ChlorideCl − FluorideF−F− BromideBr − OxideO 2− Polyatomic anions CarbonateCO 3 2- Hydrogen carbonate HCO 3 − bicarbonate HydroxideOH − NitrateNO 3 2- PhosphatePO 4 3- SulfateSO 4 2- Anions from Organic Acids EthanoateCH 3 COO − acetate MethanoateHCOO − formate EthandioateC 2 O 4 −2 oxalate CyanideCN - Common Cations Common NameFormulaAlternative name Simple Cations AluminiumAl 3+ CalciumCa 2+ Copper(II)Cu 2+ cupric HydrogenH+H+ Iron(II)Fe 2+ ferrous Iron(III)Fe 3+ ferric MagnesiumMg 2+ Mercury(II)Hg 2+ mercuric PotassiumK+K+ kalic SilverAg + SodiumNa + natric Polyatomic Cations AmmoniumNH 4 + HydroniumH3O+H3O+

30. Covalent compounds (usually non-metals)  CO2  H2O  CO  NH3  SO2  SO3  CH4

31. Equations for lab

32. Balancing chemical equations

33. Balanced equations show the mole ratio of reactants and products Hydrogen + Oxygen  Water 2 H2 + O2  2 H2O Image: http://labspace.open.ac.uk/mod/resource/view.php?id=438900

34. 2 H2 + O2  2 H2O green numbers = subscripts cannot be changed (a compound has one formula- changing the formula changes the compound) red numbers = coefficients changes to balance the reaction (coefficients valid only for a specific reaction)

35. Balancing a chemical equation Propane + oxygen  carbon dioxide + water _ C 3 H 8(g) + _ O 2(g)  _ CO 2(g) + _ H 2 O (l)

36. C 3 H 8(g) + 5 O 2(g)  3 CO 2(g) + 4 H 2 O (l) What does an equation tell us about molecules in the reaction?  you need 5 oxygen molecules for 1 molecule of propane  1 propane molecule will produce 3 carbon dioxide molecules and 4 Water molecules  2 molecules of propane produce 6 molecules of carbon dioxide  1 mole of propane produces 3 moles of carbon dioxide

37. Measuring chemical quantities

38. Measuring chemical quantities: solids  in grams  using a balance (precision ±0.01g or ±0.001g) Image: http://en.wikipedia.org/wiki/Weighing_scale

39. Measuring chemical quantities: liquids  in litres (L) or decimetres cubed (dm 3 )1L = 1dm 3  In mL or centimetres cubed (cm 3 ) 1mL = 1cm 3  1000 mL = 1L Images: http://commons.wikimedia.org/wiki/Category:Laboratory_glassware

40. Converting mass to volume  volume = mass x density  volume of pure water is 1.0 gcm -3

41. Solutions  a solute dissolved in a solvent gives a solution  units of concentration grams per litre (gL -1 )  or moles per decimetre cubed (moldm -3, M)

42. Types of chemical reaction

43.  -synthesis  -decomposition  -displacement  -double displacement (special type acid-base)  -combustion

44. Links  Powers of ten http://www.powersof10.com/http://www.powersof10.com/  hydrogen explosion http://www.youtube.com/watch?v=DjcztiNGg_8 http://www.youtube.com/watch?v=DjcztiNGg_8  states of matter phet http://phet.colorado.edu/en/simulation/states-of-matter http://phet.colorado.edu/en/simulation/states-of-matter