CHEMISTRY

1. CHEMISTRY AN INTRODUCTION

2. Chemistryis the study of matter, its properties, and its changes or transformations. • Matter is anything that has mass and takes up space. • All types of matter have 2 types of properties, physicalandchemical. • A physical property is a characteristic that you can sense. A physical changeis one that does not change the chemical properties of the substance, one in which you can turn back to the original.

3. Some examples of physical properties are: • State at room temperature (solid, liquid, gas) • Colour • Odour • Lustre • Solubility • Melting/boiling points

4. A chemical property is a behaviour characteristic that happens when that substance changes into a different substance. This behavioural change is known as a ­chemical change. • The starting substance is known as the reactant and that final substance is known as the product. • E.g. a nail left out in the rain • Reactants – iron and oxygen • Product – rust (iron III oxide)

5. Chemists use chemical teststo identify unknown gases or other substances that have been produced from a chemical reaction. • WHMIS is used to label potential dangers to human health. Symbols are placed on products to inform their users what affects they can have on their health. WHMIS stands for Workplace Hazardous Materials Information System.

6. Some matter can be classified as pure substances. A pure substance is one that is made up of all of the same particles. Pure substances can be classified into 2 groups, elements or compounds. • Elements are pure substances that cannot be broken down into a more simple substance. All of the elements found on the periodic table cannot be broken down further into more simple substances (e.g. H, C, Au). • Compounds are also pure substances that contain 2 or more different elements within them (e.g. carbon dioxide CO2).

7. SEAT WORK • Read pages 142-143 • Add bolded terms to term page • Copy the flow chart of the classification of matter into your notebook (pg. 143) • Q’s #1-3 on page 153 • Complete your Journal #1 for submission

8. Elements and the Periodic Table • The Periodic Table of the Elementsis a structured arrangement of the elements. This organised way of placing the elements allows us to explain and predict the physical and chemical properties. • The table is categorised into several groups. These groups are known as chemical families. Chemical families are arranged in vertical columns. • Alkali metals • Alkaline earth metals • Noble gases • Halogens

9. PROPERTIES OF METALS AND NON-METALS

10. The Atom • The elemental atom is made up of 3 particles, ­protons (+), neutrons, and electrons (-). • The protons and neutrons are found in the atom’s nucleus. • The electrons orbit the positively charged nucleus in electron shells. 6P 6N

11. Bohr-Rutherford Diagrams • The Bohr Diagrams - a way of representing the arrangement of electrons in the various arrangement • 1st orbit = maximum of 2 electrons • 2nd orbit = maximum of 8 electrons • 3rd orbit = maximum of 8 electrons • electron orbits want to be full to be happy (HAPPY = STABLE)

12. Let’s Try it! • Draw the following Bohr-Rutherford Diagrams: • Lithium • Nitrogen • Argon

13. Lithium • Atomic Number - • Atomic Symbol - • Draw it

14. Nitrogen • Atomic Number – • Atomic Symbol – • Draw it

15. Argon • Atomic Number - • Atomic Symbol - • Draw it

16. Creating a “HAPPY” Atom • Lets use Sodium and Chlorine – Table Salt • Draw both atoms • Are either HAPPY? • How do we make them HAPPY?

17. Ionic vs. Molecular • An Ionic Compound is a compound that is made up of positive and negative ions that have resulted in the transfer of electrons from a metal to a non-metal. The positive and negative ions are attracted to each other because they have opposite charges (like magnets). • A Molecular Compoundis formed when non-metals combine with other non-metals.

18. SEAT WORK #1 • Using your periodic table complete a table that will hold the 1st 20 elements. Check it with a peer!

19. Seat Work #2 • Complete your Student information sheet and hand in to Miss Klein. • Read section 4.1 in Pearson Text pg. 140-152. • Add terms to term sheet. • Complete Q’s #2,7,13,14 pg. 153

20. Ionic, Polyatomic, and Molecular are on Overhead/Student Notes

21. Word Equations • A word equationis a way of representing a chemical reaction. It tells you what chemicals react and which are products.  Reactants → Products Sodium hydroxide + Copper (II) sulfate Sodium Sulfate + Copper (I) hydroxide • E.g. Write a word equations for making a peanut butter sandwich…

22. Conservation of Mass • A scientific lawis a general statement that sums up the conclusions of several experiments or an observed pattern. • The law of conservation of massstates that in a chemical reaction the total mass of the reactants ALWAYS equals the total mass of the products.

23. Conservation of Mass • the total number of atoms doesn’t change from reactants to products • atoms are rearranged • reactant molecules can break apart to form different molecules methane + oxygen → water + carbon dioxide CH4 + O2(g) → H2O + CO2 + light + heat

24. ___CH4 +___ O2(g) → ___H2O + ___CO2 + light + heat

25. Thinking Questions... • When a log burns in a fire, the ashes have a much lower mass than the log. Why? • A solid has as mass of 35g. When it is mixed with a solution, a chemical reaction occurs. The total final product has a mass of 85g, what was the mass of the solution? • Why does bread rise when it is baked? How do you think the mass of the bread compares to the original total mass of the ingredients in the recipe?

26. SEAT WORK • Read pages 172 -175 in the Pearson text • Answer Q’s #1-5 on pg. 175 • Complete Word Equation w/s • Complete Counting Atoms w/s

27. Quick Review of Yesterday Writing Word Equations • Use what you have learned, rules and data tables! Reactants → Products E.g. Aluminum combines with chlorine. Aluminum + Chlorine → Aluminum chloride Al + Cl2 → AlCl3

28. Balancing Chemical Equations • From a word equation, we can write a skeleton equation, by replacing each name with a new formula. E.g. Methane + Oxygen gas → Carbon dioxide + Water CH4 + O2 → CO2 + H2O

29. There is a problem though, • The law of conservation of mass states that the mass of the reactants must equal the mass of the products. • Our formula above then is UNBALANCED. To BALANCE our equation we need to count atoms and change the number of atoms in the equation. We do this by using coefficients. • A coefficient is a number written in front of a chemical symbol or formula.

30. Let’s Try it… CH4 + O2 → CO2 + H2O Counting Atoms Reactants Products C C H H O O

31. Balancing Equation Steps • write out the word equation for the reaction • write out the chemical skeleton by replacing the names with the formula • count the number of atoms for each element on the reactant side and the products side • multiply the formulas by the appropriate coefficient to balance the atoms on both sides of the equation

32. You Try… • Nitrogen mixes with Hydrogen gas to yield ammonia • Phosphorous mixes with Oxygen gas to yield Phosphorous oxide • Potassium mixes with Chlorine gas to yield Potassium chloride

33. SEAT WORK 1. Counting Atoms w/s 2. Read pages 176-182 in Pearson text • Pg. 176 # 1-3 • Pg. 179 # 1-3 • Pg. 180 # 1-4 • Pg. 181 # 1-4 • Pg. 182 # 1-4 3. Balancing Equation w/s

34. Factors that Affect the Rate of Reaction • The Kinetic Molecular Theory states that particles are constantly moving and that they move more quickly at higher temperatures. • When particles move about they collide with one another. If they are moving slowly or are very stable they just bounce off each other. If they are moving quickly they are more likely to react. A very small fraction of the collisions are effective.

35. The Collision Model states that: • the rate of reaction is affected by the number of collisions of reactant molecules • molecules in a gas or liquid are constantly colliding with each other • if 100% of collisions were effective everything would always be reacting

36. There are 2 ways of making reactions go faster: • increasing the number of collisions • increasing the number of effective collisions H2 I2 Collision Effective Collision

37. There are 4 factors that affect the rate of a chemical reaction: • Temperature • Concentration • Surface area • Catalyst

38. TEMPERATURE temp = E = speed = reaction temp = E = speed = reaction e.g. Fridge slows down the spoiling of food CONCENTRATION amount of material in a given space # molecules = reaction CATALYST

39. SURFACE AREA • the particles in a sample that are exposed and ready to collide • SA = speed = reaction CATALYSTS • rate of controlling substance • rate of reaction without acting as a reactant • enzymes are catalysts e.g. Amylase in your saliva breaks down starch into sugar

40. Your Turn… • SEAT WORK • Review Questions pg. 190 • Q’s #1,2,5,8,10,12,14,18 • Journal #2 • Title Page • Finish Lab from yesterday

41. Properties of Acids and Bases • Acids • substance that has a pH < 7 • tastes sour • turns blue litmus paper red • strong acids are a good conductor of electricity • reacts with a base to form salt and water • can be corrosive

42. Properties of Acids and Bases • Bases • substance that has a pH > 7 • tastes bitter • slippery when rubbed between fingers • strong bases are a good conductor of electricity • can be corrosive

43. Your Tongue… • Your tongue is the best tester of a substance to determine whether it is an acid or a base. • Your tongue has designated zones that only detect certain types of tastes. • yellow – bitter • blue/green – salty • green – sweet • red - sour

44. Taste Testing… • Using a Q-tip try each of the solutions and identify which part of the tongue you can taste it the best. Also decide which on is a strong acid and which is a strong base. • Do not double dip!!

45. Your Turn… • Read 5.1 Acids and Bases (Pearson) • Q # 3-9 pg. 203 • Read 5.2 Neutralization Reactions (Pearson) • Make your own notes • Q#1-10

46. Antacids: How do they work? • When you have a meal your body goes through a process called digestion. • When your food enters your stomach you body creates hydrochloric acidto help with the chemical break down of your food to extract energy. • HCl has a pH of about 1-2. If there is too much acid in your stomach you can experience heartburn.

47. Heartburn occurs when the acidic food mixture gets pushed up into your esophagial area. Your esophagus does not have a protective lining like your stomach does so you feel a burning sensation in your throat and chest. • Heartburn has nothing to do with your heart, so is the name still appropriate? More and more doctors are pushing the name “acid reflux”which is a better representative name. • Antacids are used to neutralise a very acidic environment. When an antacid begins to neutralise it moves the pH closer to 7.

48. LAST LABS OF THE UNIT… there are 3… • In your group you are going to have to be organized to get through these labs. • Antacid Lab • Indicator Lab • Neutralization Lab

49. Chemistry Extension: Lewis Dot Diagrams • The most important shell in a Bohr-Rutherford diagram is the outer shell or Valence Shell. • To save time, energy, and space we move away from the B-R diagram and begin to draw the Lewis Dot Diagram (aka electron dot diagram).

50. How to Draw Lewis Dot… • Write the element symbol • Calculate how many electrons are in the outermost shell (valence shell) • Using dots to represent valence electrons, place dots around the 4 directions, one side at a time, staring with 12 o’clock • Decide on how to best create a stable (happy) atom