My Chemical World

1. My Chemical World

2. Matter “It Don’t Matter” - Donovan Frankenreiter Chorus: I said If it don't matter to you It don't matter to me If it don't matter to you It don't matter to me

3. Matter Matter is anything that has mass and volume Mass is the amount of material in a substance (unit: kg) Volume is the amount of space occupied by a substance (units: L, cm3, mL, cc)

4. Density • Density is the amount of mass packed into a certain volume. • Gold more dense than feathers • Less dense solids/liquids/gases float in more dense liquids/gases • Density = mass (g) volume (cm3) • Unit: g/cm3 • Ice (0.9g/cm3) floats in water (1.0g/cm3) because it is less dense • 1mL of water = 1g

5. Source: ODT 17 Nov 2006 - Northernmost iceberg

6. Source:http://www.touchnote.com/files/assets/RGS019.jpg

7. Measuring Density #1 • Turn to pg 41 Science World 9 • Copy: title, aim, data table, Then: do the experiment • *Complete: Questions 1-3 Marble 5.3g 30.0mL 31.9mL 1.9mL 2.8g/mL Remember: density = mass / volume

8. Background: Rocks (eg Basalt) have a specific density Question: Could we use this to identify a rock? If Yes: How? Example Rock Densities: Basalt: 3.0g/cm3 Granite: Limestone: 2.5-2.7g/cm3 Pumice: 0.2 g/cm3 Obsidian: Schist: 2.7g/cm3 Measuring Density #2

9. Solids • Particle packed tightly, Fixed pattern • Strong forces hold the particles together • They vibrate in fixed positions • Examples: rubber, iron, ice, chalk

10. Liquids • Particles move & slide past each other • Particles still close but not fixed • Weaker forces than a solid • Examples:alcohol, gasoline, oil

11. Gases • Particles are far apart • The particles move quickly • Almost no forces holding them together • They collide with each other and the walls of their container • Examples: air

15. Particle Theory of Matter: 1 All matter is made of particles – they are too small to see 2 There are spaces between the particles 3 There are forces holding particles together 4 The further apart the particles are the weaker the forces holding them together 5 Particles are always moving 6 At higher temperatures particles move faster than at low temperatures

16. Changes of State Key: Blue= + heat Red = - heat Reverse sublimation Reverse sublimation GAS (water vapour)

18. Alkanes

19. Explaining Changes of State • When particles heat up they move faster. With enough vibration solid particles start to slip and slide past each other and they become a liquid (melting). • With more heat the liquid particles move fast enough to leave the liquid and they become a gas (evaporation).

20. Cooling makes particle move slower. With enough cooling the fast moving particles in a gas slow down and come closer (condensation). With more cooling the particles stop slipping and sliding and become fixed – they are solid (freezing) • When heated most substances expand (but the particles stay the same size). When cooled most substances contract.

21. Temperature During State Changes • Turn to page 51 in Science World 9 • Explain the graph: • What is happening between AB, BC, CD? • What state is the wax at A,B,C,D? • Explain the flat portion of the graph line. • ?? Could we show this for H2O ??

24. Hydrogen • 90% of universe is H • Colourless • 15x less dense than any other substance • Flammable • When burnt: hydrogen + oxygen  water (hydrogen means “water generating”) • Used as a clean burning fuel (space shuttle, cars), margarine, floating weather balloons (airships use helium – not explosive)

25. Making Hydrogen • Turn to pg 168 Science World 10 • Copy: heading, aim, Then: do the experiment • Complete: Questions 1-5 (properly sketch & label for question 1)

26. Oxygen • Makes up 21% of air • Colourless, odourless • Very reactive • Combustion (burning) is when O2 reacts with other substances producing light & heat • Animals need oxygen for respiration to get energy (humans use 20 litres per hour when resting) • In space there is no oxygen so rockets need a supply of oxygen as well as hydrogen fuel • Corrosion of metals (eg rusting) is when metals react slowly with oxygen

27. Making Oxygen • Turn to pg 170 Science World 10 • Copy: heading, aim, Then: do the experiment • Complete: • Copy method diagram (properly sketch & label) • Questions 1-2

28. Carbon Dioxide • Odourless, colourless, 0.03% of air • Produced in fermentation yeast use sugar and produce CO2 (bread rises, bubbles in drinks) and alcohol (wine, beer…) • Used in photosynthesis: • CO2 + H2O  glucose + O2 • Produced in respiration: • glucose + O2 CO2 + H2O + energy (*ATP)

29. Making Carbon Dioxide • Turn to pg 172 Science World 10 • Copy: heading, aim, method diagram • Then: follow the method and complete all tasks with a red hand (write in your book, full sentences)

30. Heat & Temperature What’s heat? The amount of EK (kinetic energy) particles have What’s temperature? How hot/cold or the average EK of the particles

31. Heat Transfer Heat only transfers from hotter to colder objects in these 3 ways: Conduction Heat energy (EK) passed on when neighbouring particles bump each other. (solids mostly) Convection Heat gas/liquid  less dense  rises (draws cool material toward heat source)  cools more dense  sinks (cycle repeats to give “convection currents” Radiation Hot objects emit heat as infra-red light (travels at light speed, & through a vacuum)

33. Physical Changes • Properties may change • Substance stays the same • No new substance forms • Change is usually reversible • Shape / state change • eg: water freezing...

34. Chemical Changes • New substances are made • Heat / light may be produced • Can’t be easily reversed • May be a colour change • Bubbling / fizzing • eg: burning wood…

35. What is a Mixture?

36. Solutions • Use the glossary at the back of the textbook to DEFINE each of the following, and give an EXAMPLE. • Dissolve • Solution • Solute • Solvent • Soluble • Insoluble • Suspension

37. Soluble or Insoluble? • Turn to pg 63 Science World 9 • Copy: title, aim • Then: Part A - follow the method making sure you complete the data table recording “soluble, slightly soluble, insoluble” for all the substances supplied, repeat with ethanol instead of water for part B (pg64) • Complete: Questions & Conclusions (pg64) FULL answers

38. Solubility • Use the glossary at the back of the textbook to DEFINE each of the following, and give an EXAMPLE. • Dilute • Concentrated • Saturated Solution • Unsaturated (not in glossary) • Solubility (+ write what generally happens to this as temperature increases) • Super Saturated (not in glossary) • (if you finish early add images / pictures for each)

39. Finding Solubility • Solubility is the amount of solute that can dissolve in a set amount of solvent at a particular temperature. • Eg: sugar solubility: • 2kg per litre of water at 20ºC • 5kg per litre of water at 100ºC (Science World 9) • How could we find solubility? • Solute / solvent choice? • End point? • Units?

40. Solubility of Salt Aim: To find the solubility of salt Method: • Put 100mL water in a beaker (A) • Weigh this. • Add salt until no more dissolves. • Weigh beaker. (B) • Calculate B-A. This is the solubility in grams per 100mL (of salt in water) Result: Solubility of salt in H20 at ____ degrees Celsius: _____ g/ 100mL Question(s) Predict whether the solubility would increase if temperature is increased

41. Solubility of two salts at different temperatures

42. Separating Mixtures

43. Separating Suspensions • Decanting • Pouring off a liquid, leaving solid behind • Centrifuging • Spinning suspension at high speed causing solids to settle quickly. Liquid is then decanted • Filtering • Separating solid from liquid using a filter • filtrate: the liquid that has passed through a filter • residue: the solid left behind after filtering Filtering: http://youtube.com/watch/?v=6wAuPMAB-Ls&feature=related (6:30)

44. Filtering & Decanting • Turn to pg 68 Science World 9 • Copy: title, aim • Then: • Part A: follow the method • Part B: follow the method • Complete: Questions & Conclusions (pg69) FULL answers

45. Separating Solutions • Distillation - Separating the parts of a solution by: • Evaporating the liquid, then: • Condensing the liquid in a separate container

46. Evaporation & Distillation • Turn to pg 71 Science World 9 • Copy: title, aim, Part A title, method diagram (label it) • Then: • Part A: follow the method • Complete: Questions & Conclusions (pg72) FULL answers • Then: • Part B: copy title, follow method OR watch demo • Complete: Questions & Conclusions (pg73) FULL answers

48. Making Crystals • Crystals of a solute form when a solution becomes so concentrated that the solute can’t stay dissolved anymore. • This is achieved by: • evaporating solvent • heating, adding solute to make the solution super saturated and then allow it to cool. • Crystal size depends on rate of formation • Fast: small crystals • Slow: large crystals

49. 5H20.CuSO4 • Take hydrated copper (II) sulphate crystals in a test tube and heat. The blue crystals in the test tube start turning white on heating. Water vapours released on heating condense on the cooler part of the test tube. Collect the water drops in a dish. The crystalline copper sulphate turns to a white amorphous form. • Allow the white amorphous powder in the test tube to cool down and then add the water collected in the dish to it; white amorphous powder turns back to blue crystalline form.

50. Solar Water Distiller • Having viewed the video you are now to get into groups of three and design a practical solar distiller. • Complete a one page plan (aim, equipment, method) showing how you will carry this out. • Supplied equipment. 500mL of coloured water (or water mixed with soil) + regular lab equipment (anything else must be brought in by you).