1. Types of Compounds 15/10/2015 There are two types of compounds 1. Ionic Compounds These are compounds where electrons are transferred from one atom to another to give each atom full outer shells. This forms a (+) ion and a (-) ion. These oppositely charged ions are attracted to each other to form an ionic bond Eg Na = 2,8,1 Now Na + is formed Cl = 2,8,7 Now Cl - is formed The Na + and Cl - come together to form NaCl (now we don’t write the charges) The Na electron is transferred to the Cl atom

2. Ionic compounds are always between a metal and a non metal eg Na (metal) Cl (non metal) make NaCl In year 11 you will be given a table of ions – you don’t have to remember them. But you must know how to write balanced formula for ionic compounds using these ions 1+2+3+2- Na + Mg 2+ Al 3+ O 2- Li + Ca 2+ K+K+ Fe 2+ Cu 2+ Zn 2+ Pb 2+

3. 1+2+3+2-1- Na + (Sodium) Mg 2+ (magnesium) Al 3+ (aluminium) O 2- (oxide) OH - (hydroxide) Li + (Lithium) Ca 2+ (calcium) Fe 3+ (ferric) SO 4 2- (sulfate) Cl - (chloride) K + Potassium Fe 2+ (ferrous) CO 3 2- (carbonate) F - (fluoride) Cu 2+ (copper) NO 3 - (nitrate) Zn 2+ (zinc) Pb 2+ (lead)

4. Task : write the chemical formula for sodium oxide in your book Step one: Write out the two ions from the chart with their charges ie Na + and O 2- Step two : Make the two charges balance (in other words are there the same number of (+) as (-) ) Na = +1 and O = -2 no they don’t balance. Na = +1 and O = -2 no they don’t balance. Step three: Now the seesaw doesn’t balance You must add an extra Na+ ion to make the (+) and (-) balance which ion do you think you will need to add to the seesaw?

5. Yes you are correct you need to add one Na + to the left hand side of the seesaw Now you write the formula for sodium oxide as Na 2 O This tells us in each particle of sodium oxide (Na 2 O) There are two Na + ions and one O 2- ion

6. Task : Find the formula for aluminium oxide Step one Write out the ions from your table ie Al 3+ and O 2- Step two : Make the two charges balance (in other words are there the same number of (+) as (-) ) Al = +3 and O = -2 no they don’t balance. Al = +3 and O = -2 no they don’t balance. Step three: Add ions to both sides until the charges balance Al 3+ O 2- Al 3+ O 2- Al 2 O 3 Aluminium oxide

7. You try this one write out each step : Find the formula for magnesium nitrate Step one Write out the ions from your table ie Mg 2+ and NO 3 - Step two : Make the two charges balance (in other words are there the same number of (+) as (-) ) Mg = +2 and NO 3 - = -1 no they don’t balance. Mg = +2 and NO 3 - = -1 no they don’t balance. Step three: Add ions to both sides until the charges balance Mg 2+ NO 3 - Mg(NO 3 ) 2 NO 3 - Then write formula

8. Starter Task : Write the chemical formula for Calcium hydroxide in your book Step one: Write out the two ions from the chart with their charges Step two : Make the two charges balance by adding ions Step three: Write the finished formula without the charges

9. You can quietly read the following 6 slides or you can copy them down

10. Covalent bonds involve atoms sharing electrons to form molecules. Molecules can be compounds made of two or more different atoms eg CO 2, H 2 O, C 6 H 12 O 6 etc Molecules can also be elements where 2 identical atoms are covalently bonded together eg H 2, N 2, O 2, Cl 2 etc Types of Compounds 2. Covalently bonded Compounds

11. Remember covalent bonds involve the sharing of electrons This is how both carbon and hydrogen achieve full valence (or outer) shells in CH 4. When atoms form covalent bonds they form molecules.

12. First draw both atoms with their valence electrons How to draw the bonding structure of a covalent molecule

13. 1. In pairs use the model atoms to make a methane (CH 4 ) molecule C atoms are black H atoms are white Use the long grey bonds to join them 2. Then make an H 2 O molecule H = white O = red 3. Then make a SO 2 molecule S = yellow O = red 4. Then make an H 2 molecule Show me when you have finished each one

14. Then make a carbon dioxide (CO 2 ) molecule Then make a glucose (C 6 H 12 O 6 ) molecule (hint make a ring of 6 carbons) Show me when you have finished each one

15. Covalent bonding in methane (CH 4 ) From the carbon atomic number we find: C 6 12 carbon has an electron arrangement of 2, 4 This means carbon has 4 electrons in its valence (or outer) shell We can draw the 4 valence electrons of carbon like this: How many electrons does carbon need in its valence (or outer) shell? Ans: 8 electrons

16. H 1 1 hydrogen has an electron arrangement of 1 This means hydrogen has 1 electron in its valence (or outer) shell From the hydrogen atomic number we find: We can draw the valence electron of hydrogen like this: How many electrons does hydrogen need in its valence (or outer) shell? Ans: 2 electrons

17. Place 4 hydrogen atoms around the C atom so that each H shares an electron with a C electron Each H atom shares one electron with one C electron to give each H a full valence shell of 2 electrons This sharing of electrons between H and C also means the C atom has a full valence shell of 8 electrons Can you see that both H and C atoms have full valence shells by sharing their electrons?

18. Ions and Molecules Ions Write down the following filling in the gaps. Ions are atoms that have g_____ or l_____ electrons to form p_______ or n________ ions 3 examples of ions are _________ion symbol ( ), ________ ion symbol ( ) and _________ ion symbol ( ). Choose from : smallest, neutrons, covalent, electrons, gained, loss, negative, positive, valence, outer, protons, water, hydrogen gas, H 2, CO 2, H 2 O

19. Atoms, Ions and Molecules Atoms Write down the following filling in the gaps. Atoms are the s________ particles that make up all things. They consist of ________ and _________ in the nucleus with e________ in shells around the nucleus. 3 examples of atoms are _________ symbol ( ), ________ symbol ( ) and _________ symbol ( ). Choose from : smallest, neutrons, covalent, electrons, gained, loss, negative, positive, valence, outer, protons, water, hydrogen gas, H 2, CO 2, H 2 O

20. Atoms, Ions and Molecules Molecules Write down the following filling in the gaps. Molecules are where two or more atoms share electrons in a c________ bond to give both atoms full v______ or o______ shells. 3 examples of molecules are w_______ formula ( ), c________ d_______ formula ( ) and h______ g___ formula ( ). Choose from : smallest, neutrons, covalent, electrons, gained, loss, negative, positive, valence, outer, protons, water, hydrogen gas, H 2, CO 2, H 2 O

21. 15/10/2015 What is an ion? An anion is an atom that has gained electron(s) to form a (-) ion e.g Cl - (Chloride) e.g Cl - (Chloride) S 2- (Sulfide) S 2- (Sulfide) or a cation is an atom that has lost electron(s) to form a (+) ion e.g Na + (Sodium) e.g Na + (Sodium) Fe 2+ (iron (ll) ion) (aka Ferric ion) Fe 2+ (iron (ll) ion) (aka Ferric ion) Fe 3+ (iron(lll) ion ) (Ferrous) Fe 3+ (iron(lll) ion ) (Ferrous)

22. Compounds can be two types – Copy this neatly into your book 1. Compounds can be Ionic Ionic compounds form when atoms lose and gain electrons to form charged (+) and (-). These oppositely charged ions are attracted together to form an ionic bond. Ionic bonds always occur between a metal and non metal. Eg Na (+) and Cl (-) come together to form NaCl

23. Compounds can be two types – Copy this neatly into your book 2. Compounds can be Covalent These atoms share electrons so that each atom has a full outer shell. This sharing of electrons is called a covalent bond. Covalently bonded atoms form molecules. Molecules are always between non metal atoms. Examples of molecules are CH 4 methane, H 2 O water, CO 2 carbon dioxide

24. 15/10/2015 Atoms and elements A substance made of one type of atom is called an element e.g. a piece of Aluminium (symbol Al) consists of only aluminium atoms bonded together and is called an element.

25. 15/10/2015 Molecules Some elements are unstable as single atoms and only exist as 2 atoms covalently bonded together to form a molecule. These are usually gases These are usually gases e.g H 2, N 2, Cl 2, O 2 e.g H 2, N 2, Cl 2, O 2

26. 15/10/2015 Compounds and Molecules Some compounds are molecules that contain 2 or more different atoms covalently bonded together. Some common molecular compounds are: Some compounds are molecules that contain 2 or more different atoms covalently bonded together. Some common molecular compounds are:  CO 2 (carbon dioxide)  H 2 O (water)  CH 4 (methane)  C 6 H 12 O 6 (glucose)

27. 15/10/2015 Balancing Reactions Mg + O 2 Zn + HCl Fe + Cl 2 NaOH + HCl CH 4 + O 2 Ca + H 2 O NaOH + H 2 SO 4 CH 3 OH + O 2 MgO ZnCl 2 + H 2 FeCl 3 NaCl + H 2 O CO 2 + H 2 O Ca(OH) 2 + H 2 Na 2 SO 4 + H 2 O CO 2 + H 2 O 2 2 2 3 2 2 2 2 2 2 2 2 4

28. 15/10/2015 Simple formulae to learn H 2 O CO 2 NH 3 H 2 O 2 N 2 SO 2 Water Carbon dioxide Ammonia Hydrogen Oxygen Nitrogen Sulphur dioxide NaCl CaCl 2 MgO HCl H 2 SO 4 HNO 3 NaOH Ca(OH) 2 CaCO 3 Al 2 O 3 Fe 2 O 3 Sodium chloride Calcium chloride Magnesium oxide Hydrochloric acid Sulphuric acid Nitric acid Sodium hydroxide Calcium hydroxide Calcium carbonate Aluminium oxide Iron oxide

29. Acids Acids release hydrogen ions (H+) in water to give acidic solutions Common Lab Acids are: Sulfuric acid (formula H 2 SO 4 ) Nitric acid (formula HNO 3 ) Hydrochloric acid (formula HCl) These are strong acids because they form a lot of H+ ions in water Eg HCl (l) H + (aq) + Cl - (aq) Eg H 2 SO 4 (l) 2H + (aq) + SO 4 2- (aq)

30. Acids Other Acids found around the home are: ethanoic acid (formula CH 3 COOH ) this is the acid found in vinegar. Tartaric acid (formula C 4 H 6 O 6 )used in cooking Citric acid ( formula C 6 H 8 O 7 ) this is the acid found in oranges and other fruits. ascorbic acid is another acid known as vitamin C. These acids are called weak acids because they form a small number of H+ ions in water

31. Bases Bases are substances that release hydroxide ions (OH-) in water. Eg NaOH (s) Na + (aq) + OH - (aq) Eg KOH (s) K + (aq) + OH - (aq) Strong bases give off lots of OH- ions and weak base give off less OH- ions Common strong bases are: Sodium hydroxide (NaOH) Potassium hydroxide (KOH) Ammonium hydroxide (NH 4 OH) Many cleaning agents are bases eg oven cleaners, window cleaners

32. The pH Scale The amount of H+ ions given off by an acid are measured by the pH scale 1 on the pH scale means there are a lot of H+ ions in the water and the solution is said to be acidic 14 on the pH scale means there are very few H+ ions in the water but a lot of OH- ions creating a basic solution

33. 1234567891011121314 Draw the pH scale below your book 1234567891011121314 acid Neutral Eg water base The colours below are the colours for the different pH numbers with universal indicator this indicates how acidic or basic a solution is Task – gently shade your pH scale these colours

34. 1234567891011121314 1234567891011121314 acidneutralbasic Anything less than 7 on the pH scale is called an acid Weak acid Strong acid neutral

35. 1234567891011121314 acidneutralbasic Indicators can also tell us how many OH- ions a base will give off and this gives us an indication of how basic a solution is. 1234567891011121314 Weak base Strong base neutral

36. Which beaker contains the acid and which one contains the base? Beaker 1 Blue litmus Beaker 2 Red litmus BaseAcid Which beaker has more OH- ions? Which beaker has more H+ ions? (H+)(OH-) Litmus paper is another indicator Remember blue litmus paper tests for acids Red litmus tests for bases

37. Litmus paper can also tell us Whether we Have an Acid or a base. Litmus paper can be red or blue Acids turn blue litmus paper red Bases turn red litmus paper blue

38. Neutralisation hydroxide (OH - ) ions are the opposite to H + When there are equal amounts of H+ and OH- ions in a solution they will react to form pure water (H 2 O) in a neutralisation reaction – the neutralisation reaction is below H + + OH - H 2 O (water is neutral and has a pH of 7) So bases eg NaOH, KOH can neutralise acids! and acids eg HCl,H 2 SO 4 can neutralise bases! From acid From base

39. Gas tests All carbonates eg _______ react with any acid to from CO 2 (carbon dioxide) gas. The limewater test bubbled CO 2 through limewater How do you test for CO 2 ? CaCO 3 Give a balanced equation for an acid/carbonate reaction CaCO 3 + 2HCl CaCl 2 + CO 2 + H 2 O CO 2 + Ca(OH) 2 CaCO 3 + 2H 2 O

40. How do you test for O 2 ? (Oxygen) The glowing splint test KMnO 4 MnO 2 + O 2

41. Finally how do you test for H 2 (hydrogen)? The pop test Give a balanced reaction for the magnesium and hydrochloric acid reaction Mg + 2HCl MgCl 2 + H 2 Give a balanced reaction for the combustion of the hydrogen

42. Physical Property of metal Meaning malleableMeans the metal can be bent ductileMeans the metal can be made into wires ConductivityConducts both heat and electricity lustrousShiny solidAll are solid except Hg Physical Properties of metals

43. Metal Structure A metal consists of a regular arrangement of positive ions held together by a 'sea' of electrons.

44. Metal structure Starter Metals consist of p______ metal ions surrounded by n______ electrons. The attraction of the e_______ for the p_____ ions acts like a glue that holds metals atoms together

45. Activity On the periodic table in your book colour the metals red and nonmetals blue leave the metalliods (these are elements found on the border line between the metals and non metals) white. Give names to the following metal symbols: Al - Zn - Ag - Ni - Ca - Cu – Fe - Li - Mg – Pb - Na - Au - Aluminium Nickel Iron Lead Calcium Zinc Lithium Sodium Silver Copper Magnesium Gold

46. Metal Structure A metal consists of positive ions held together by a 'sea' of electrons. The electrons account for the lustrous appearance of metals Because the electrons can move freely they conduct electricity, however the positive ions can only vibrate in the one spot. This means metals also conduct heat as well Note This type of metal bonding between positive ions and electrons in metals is strong giving metals high melting points.

47. Why metals conduct heat Demo by heating spatula with paper clips attached by vasoline The word particle in this passage refers to the metal ions.

48. As the metallic bonds do not act in a particular direction, the rows of positive ions can slide over one another easily. This allows the metal to be bent or shaped. This structure allows metals to be bent (malleable) or made into wires (ductile) Why most metals can be bent or shaped

49. Metal structure Starter Metals consist of p______ metal ions surrounded by n______ electrons. The attraction of the e_______ for the p_____ ions acts like a glue that holds metals atoms together

50. Isotopes An isotope is an atom with a different number of neutrons The above are all naturally occurring isotopes of hydrogen

51. Metals and oxygen What is Rust? Rust only occurs with iron (Fe) metal. Rusting is where iron reacts with oxygen in the air to form rust (also known as iron oxide Fe 2 O 3 ) To from rust iron, water and oxygen must be present. Rust is always noticed by a reddish brown layer occurring on the surface of the iron.

52. Summary – Metal Reactions metal + oxygen metal oxide aluminium + oxygen aluminium oxide Metals and oxygen – general reaction Example

53. metal + oxygen Use the general reaction below to write both word equations then symbol equations for each of the metals reacting with oxygen calcium sodium magnesium + oxygen sodium oxide + oxygen calcium oxide + oxygen magnesium oxide metal oxide 4Na + O 2 2Na 2 O 2Ca + O 2 2CaO 2Mg + O 2 2MgO

54. zinc copper iron aluminium + oxygen zinc oxide + oxygen iron oxide + oxygen copper oxide + oxygen aluminium oxide 4Al + 3O 2 2Al 2 O 3 2Zn + O 2 2ZnO 4Fe + 3O 2 2Fe 2 O 3 2Cu + O 2 2CuO

55. Experiment: metals and water Aim: to observe the reactions of metals with water and sort out which react faster than others page 129 yellow lab book The general reaction for a metal reacting with water is: metal + water metal hydroxide + hydrogen eg Na + H 2 O NaOH + H 2

56. reaction mixture starter complete the following reaction mixture starter complete the following Li + H 2 O Ca + H 2 O Mg + H 2 O (steam) Al + H 2 O (steam) Cu + O 2 Fe + O 2 (rust forms) 2LiOH + H 2 Ca(OH) 2 + H 2 2CuO 2Fe 2 O 3 MgO + H 2 Al 2 O 3 + 3H 2 2 2 43 23 22

57. Experiment: metals and acid Aim: to observe the reactions of metals with acid and sort out which react faster than others (that is - which ones are more reactive) The general reaction for a metal reacting with an acid is: metal + acid metal salt + hydrogen

58. Summary Most metals will react with dilute acids to give off hydrogen gas and form a salt. The general formula for a metal acid reaction is Magnesium +hydrochloric acid Magnesium + chloride hydrogen gas Iron +hydrochloric acid Iron Chloride + hydrogen gas Zinc +hydrochloric acid Zinc Chloride + hydrogen gas Metal + acid Metal salt +hydrogen gas Write word and symbol equations for these acid metal reactions

59. Complete the following WORD equation. (a)ACID+METAL Give a balanced example of an acid/metal reaction Mg + 2HCl MgCl 2 + H 2 Metal salt + Hydrogen Write a balanced equation for an sulfuric acid and Iron metal reaction Then complete exercises writing balanced symbol equations on page 133 Fe + H 2 SO 4 FeSO 4 + H 2

60. Write out the following From the folowing metal list answer the questions below Li, Cu, Zn, Al, Mg, Fe, Pb 1. List the metals in order from most reactive to least reactive? 2. ____ is a metal that reacts with cold water 3. _______ is the metal that does not react with sulfuric acid. 4. ______ is the most reactive metal on the list Li, Mg, Al, Zn, Fe, Pb, Cu Li Cu Li 5. ______ is the metal that rusts Fe Most reactiveleast reactive

61. Metal oxides + water Give a balanced reaction for CaO reacting with H 2 O metal hydroxide CaO + H 2 O Ca(OH) 2 Give a balanced reaction for sodium reacting with oxygen 4Na + O 2 2Na 2 O Give a balanced reaction for H 2 SO 4 reacting with Li 2Li + H 2 SO 4 Li 2 SO 4 + H 2 Starter Summary Reactions Some metal oxides do not d _____ in water and _____ ___ produce alkaline solutions. Describe the relative concentration of H+ ions at different points of the pH scale. issolve will not

62. ACID + CARBONATE Give a balanced reaction for HCl reacting with CaCO 3 Salt + carbon dioxide + water CaCO 3 + 2HCl CaCl 2 + CO 2 + H 2 O Give a balanced reaction for HCl reacting with NaHCO 3 (sodium bicarbonate) NaHCO 3 + HCl NaCl + CO 2 + H 2 O Give a balanced reaction for H 2 SO 4 reacting with ZnCO 3 ZnCO 3 + H 2 SO 4 ZnSO 4 + CO 2 + H 2 O Acid Carbonate Reactions Complete the experiment on page 136 then questions

63. Homework for test on Friday Check out the 1.4 Achievement standard page 103 -104 (yellow lab book) Look at Specific learning out comes page 104 - 105 make sure you use to make headings for study notes and practise these Read chapter 15 Basic Chemistry (NCEA level 1 Science text) complete all questions Read Chapter 16 acids and bases and complete all questions Read Chapter 17 metals and complete all questions

64. Alloys Remember alloys are mixtures of metals and other substances Important alloys are Steel made of carbon and iron – used in many industries including car bodies Brass made of copper and zinc – used in plumbing fittings Solder made of tin and lead – used in making circuits Alloys are made to change the physical property of the metal eg solder melts lower than lead or tin

65. Read page 63 in MW to find why metals conduct electricity. The sea of negative electrons in metals allows electrical current to flow through the metal. These electrons also account for the shiny appearance of metals. Why do metals conduct electricity?

66. As the metallic bonds do not act in a particular direction, the rows of positive ions can slide over one another easily. This allows the metal to be bent or shaped. This structure allows metals to be bent (malleable) or made into wires (ductile) Why most metals can be bent or shaped

67. Neutralisation HCl + NaOH H 2 O + NaCl

68. Refresher Strong bases eg _____ have a pH of ___ and will turn universal indicator _____ common lab bases are potassium hydroxide (KOH), sodium hydroxide (NaOH) and ammonium hydroxide (NH 4 OH) Common household bases are: ____________ ___________ Window cleaner Oven cleaner Jiff KOH 14 purple

69. Universal indicator goes ____ with a strong acid and the pH will be around ____ Neutral solutions (eg pure water) go _____ with universal indicator and a pH of around _____ Strong bases go _______ with universal indicator and have a pH of around____

70. Refresher Strong acids eg _____ have a pH of ___ and will turn universal indicator _____ Weak acids eg Lemon ___ have a pH of ___ and will turn universal indicator _____ Examples of common household acids are: _____________ ______________ HCl 1 red juice 4-6 orange vinegar tartaric citric

71. Experiment finding the pH of substances - Draw the table below: Place 2 cms of water in each tube (then two drops of the test solutions) 3 drops of universal indicator in them – write then fill in your chart Solution name Colour of solution pH of Solution

72. Experiment finding the pH of substances - Draw the table below: Place 2 cms of each of the solutions below in a test tube then place 3 drops of universal indicator in them – write the colour in the chart Baking soda solution bleach milk lemonade Soft soap Jiff pH 1 pH 14 pH 3-5 pH 7 pH 10 - 12 pH 1-2 red violet/purple red green violet red Colour of solution pH of Solution

73. Strong and Weak Acids- Experiment Place 2cms of each of the 3 acids in 3 test tubes in a test tube rack – copy this table into your book - use a ruler to draw it AcidColour with Universal indicator Reaction with Mg metal Sulfuric Hydrochloric Ethanoic

74. Acid Reactions Experiment Place 2cms of each of the 3 acids in 3 test tubes in a test tube rack – copy this table into your book - use a ruler to draw it AcidObservation with calcium carbonate Sulfuric Hydrochloric Ethanoic

75. Using the white boards answer the questions: By being the first group to neatly show the correct answer Give the chemical symbols for: Give the type and number of atoms in sodium carbon copper Potassium helium iron mercury Sulfur NaCl NaNO 3 H 2 SO 4 PbCO 3 Na 2 CO 3 Al 2 (SO 4 ) 3 CH 3 COOH What can you remember?