Jumpstart

1. Objective 04/22/2013 Page 116 SWBAT review compounds and molecules to recall how they bond and their properties through notes and discussion. Jumpstart Do you remember…. what a compound is? Give an example. what a molecule is? Give an example.

2. Compounds & Molecules Packet 11 Page 1 Notebook Page 117

3. Chemistry Review- Packet 11, Page 1 • Atom- smallest particle of an element with the same properties as that element • In size the entire atom has been thought to be approximately four-billionths of an inch, meaning that approximately 250,000,000 atoms of this size must be put into line to span 1 inch. • Element- matter made of one type of atom; cannot be broken down by chemical or physical means

4. Compound vs. Molecule • Compound- matter made of two or more different elements; chemically bonded; cannot be separated by physical means; has properties different from elements that make it up • 6.2- THE STUDENT WILL EXPLAIN THAT COMPOUNDS FORM WHEN TWO OR MORE DIFFERENT KINDS OF ATOMS BOND. • Molecule- matter made of two or more elements (same or different); smallest particle of a substance with the same properties as that substance • Heteroatomic molecule- must have more than one type of atom, such as water (H2O) and carbon dioxide (CO2). • Homoatomic molecule- a molecule consisting of atoms of the same element; i.e. diatomic

5. Types of Molecules • Diatomic Molecule- simplest molecule; two of the same atoms bonded together • H2 O2 F2 Br2 I2 N2 Cl2 • HOFBrINCl twins • IHave No Bright Or Clever Friends • Hydrogen; the rest form a 7 on the periodic table: N, O, F across, then going down Cl, Br, I. • Polyatomic Molecule- Molecules containing more than two atoms are termed polyatomic molecules, e.g., carbon dioxide (CO2) and water (H2O). • 6.4- THE STUDENT WILL COMPARE AND CONTRAST MOLECULES AND COMPOUNDS.

6. 6.5- THE STUDENT WILL COMPARE THE PROPERTIES OF COMPOUNDS WITH THE PROPERTIES OF THEIR ELEMENTS. Sodium, Na Chlorine, Cl poisonous, highly irritating, gas, greenish-yellow color soft, malleable, metal, silver color, explodes in water white, cubic crystals, “salty” taste

7. 6.5- THE STUDENT WILL COMPARE THE PROPERTIES OF COMPOUNDS WITH THE PROPERTIES OF THEIR ELEMENTS. Carbon, C Hydrogen, H Oxygen, O Crystal form: graphite, diamonds; Non-crystal form: coal Gas, Colorless, Highly flammable Gas, Colorless, Odorless, Tasteless White color, Crystals, Sweet taste

8. 6.5- THE STUDENT WILL COMPARE THE PROPERTIES OF COMPOUNDS WITH THE PROPERTIES OF THEIR ELEMENTS. Sodium, Na Carbon, C Oxygen, O Hydrogen, H white, powder, crystals/ lumps soft, malleable, metal, silver color, explodes in water Crystal form: graphite, diamonds; Non-crystal form: coal Gas, Colorless, Odorless, Tasteless Gas, Colorless, Highly flammable

9. Objective 04/24/2013 Page 118 • SWBAT notice the difference between a physical and chemical changes and how it relates to compounds when combing and separating them through notes. Jumpstart A boat is sitting in a pond rusting due to sitting in water for a long period of time. Identify signs of this change. What type of change is this…physical or chemical? How do you know?

10. Physical vs. Chemical Properties & Changes Packet 11 Page 2 Notebook Page 119

11. 6.5- THE STUDENT WILL COMPARE THE PROPERTIES OF COMPOUNDS WITH THE PROPERTIES OF THEIR ELEMENTS. Sodium, Na Carbon, C Oxygen, O Hydrogen, H white, powder, crystals/ lumps soft, malleable, metal, silver color, explodes in water Crystal form: graphite, diamonds; Non-crystal form: coal Gas, Colorless, Odorless, Tasteless Gas, Colorless, Highly flammable

12. Physical Properties and Physical Changes Physical Property • observed with the senses (color, shape, odor, state/phase of matter) • phase changes (melting point, boiling point, freezing point) Physical Change • Physical changes are about energy and states of matter • You can cause physical changes with forces like motion, temperature, and pressure. • MATTER: • Alters the form or appearance of a material • Does not make the material into a new substance; the matter is the same before and after the change • Original matter can be recovered; change can be “undone”

13. Physical Changes • PARTICLES: • The molecules of the substance are rearranged, NOT atoms • EXAMPLES: • chopping wood, bending copper wire into new shapes, painting a car, ice melting into water

14. Chemical Properties and Chemical Changes Chemical Property • Observed during a chemical reaction; the way it reacts to another substance • Based on the structure of the atoms or molecules Chemical Change • any change that results in the formation of new substances • MATTER: • The matter is different; the original matter is no longer present and cannot be recovered; the change cannot be “undone” • The substances present at the beginning of the change are not present at the end

15. Chemical Changes PARTICLES • Bonds between atoms in molecules are broken, atoms are rearranged, and new bonds are made • Forms a new substance with molecules with a different structure • contains the same elements, but rearranged in new combinations EXAMPLES: Rusting of iron (oxidation), burning of gasoline in an engine (flammability)

16. Flammable vs. Combustible • The distinction is determined by how easily they ignite • Flash point- the lowest temperature at which it can produce a flame when a source of ignition is present. • Flammable- material that can easily catch fire under normal circumstances and with the help of minimal ignition source. Just a spark is sufficient enough • Flash point: below 100°F • Example: gasoline, propane • Combustible- material that will burn; but more vigorous conditions are required for an ideal combustible material to burn; A simple spark is definitely not enough. • Flash point: above 100°F • Example: paper, wood

17. 1. Physical Property 2. Chemical Property Differentiating between physical and chemical properties… hold up 1 finger for physical, 2 fingers for chemical Copper conducts electricity Iron reacts with water to form rust. Oxygen is a gas. The color of the house is red. A flagpole is 25ft tall. Steel is attracted to a magnet. Silver reacts with moisture in the air to form tarnish.

18. 6.13- TSW CLASSIFY SUBSTANCES USING THEIR PROPERTIES. X X X X X X X X X X X X X X X X X X X X

19. Homework: Packet 11, Page 3Due TomorrowPhysical vs. Chemical Changes • BOTTOM: Choose 2 examples of physical changes, and 2 examples of chemical changes. Explain why you chose chemical or physical. Support your explanation with examples or proof. Burning trees are chemically changed into other substances like carbon and ash.

20. Evidence that a Chemical Change has Occurred: Page 4 • Bubbles of gas appear • A precipitate (solid) forms • A color change occurs • The temperature changes • Light is emitted • A change in volume occurs • A change in electrical conductivity occurs • A change in melting point or boiling point occurs • A change in smell or taste occurs

21. Changes in Energy in Chemical Reactions • Endothermic- energy is absorbed • Ex. Cold pack, baking bread • Exothermic- energy is released • Ex. Burning gasoline, fireworks

22. Physical: G + B -> GB Same atoms on both sides of the equation Chemical: A + B -> C Different substances on both sides of the equation. A & B on the left form a completely different substance C on the right. Chemical and Physical Change Equations Reactants: left side (what is reacting; A & B) Products: right side (what is produced; C)

23. 1990 Law of Conservation of Mass • Matter can neither be created or destroyed, but can be changed in form. • The total mass of the material(s) before the reaction is the same as the total mass of material(s) after the reaction. Mass of Reactants = Mass of Products 2012

24. Matter is never created or destroyedin chemical reactions.  The particles of one substance are rearranged to form a new substance. • The same number of particles that exist before the reaction exist after the reaction. • Why do we need a rubber stopper in the flask? Mass of Reactants = Mass of Products

25. Symbols Used in Equations • “+” read as “plus” • Separates molecules on the same side • “->” read as “yields” • Separates reactants (left); products (right) • Numbers in front: coefficients • Physical states of compounds • Solid (s) • Liquid (l) • Gas (g) • Aqueous solution (aq) • Escaping gas () • Change of temperature ()

26. Types of Chemical Reactions • Synthesis Reaction: • Element + Element  Compound • X + Y -> XY • Decomposition Reaction: • Compound  Element + Element • XY -> X + Y • Single Displacement Reaction: • Element + Compound  Compound + Element • A + XY -> AY + X • Double Displacement Reaction: • Compound + Compound  Compound + Compound • XY + AB  XB + AY

27. 2 Na + Cl2->2 NaCl Synthesis H2CO3->H2O + CO2 Decomposition

28. Zn + 2HCl ->ZnCl2 + H2 Single Displacement NaCl + AgF->NaF + AgCl Double Displacement

29. Objective 04/24/2013 Page 120 • SWBAT notice the difference between a physical and chemical change to solve and balance the equation of reactants to products through practice. Jumpstart • An iron rod is sealed inside a mold that is put in a high-temperature furnace. The rod melts inside the mold and turns into liquid. The hot liquid iron is then allowed to cool until it becomes a solid rod again. The new rod is then removed from the mold. What difference do you think there is between the original rod and the new rod? • The new rod is lighter than the original rod • The new rod is heavier than the original rod • The new rod has the same mass as the original rod • The rod is lighter when it’s a liquid than when it’s a solid • The mass of the rod depends on how long the iron took to cool

30. Balancing Chemical Equations Packet 11 Page 4 & 6 Notebook Page 121

31. Chemical reactions… • …occur when bonds are formed or broken • …involve changes in matter • …make new materials with new properties • …involve energy changes (light or heat) • …use chemical equations to describe a chemical reaction Reactants: Zn + I2 Product: Zn I2

32. Chemical Equations • Charcoal used in a grill is Carbon. Carbon reacts with oxygen gas to make carbon dioxide. • What is the chemical equation for this reaction? C + O2 -> CO2 • This reads “carbon plus oxygen gas react to yield carbon dioxide”

33. Balancing Chemical Equations- Page 6 Because of the Law of Conservation of Matter, an equation must be balanced. It must have the same number of atoms of the same kind on both sides.

34. Steps to Balancing Equations- Page 6 • Write correct formula for reactants & products. • Find the # of atoms for each element on the left and right. • Add coefficients in front of formulas so the left has the same # of atoms as the right • HINT: Work on one element at a time • DO NOT CHANGE THE FORMULAS! • You may not change the subscripts • Changing the subscripts changes the compound. • Check your answer to see if: • The # of atoms on both sides of the equation are now balanced • The coefficients are reduced to the least common factor

35. Correct Formula • Find # of atoms on left and right • List atoms involved on each side of the arrow • Count up the atoms on each side • Add coefficients- adjust totals • Totals still aren’t equal • Add coefficients- adjust totals • Check Answers What type of rxn is this? Synthesis- S BOTH SIDES HAVE EQUAL NUMBERS OF ATOMS • Mg + O2  MgO 2 2 WE SAY THAT THE EQUATION IS BALANCED!! 1 1 2 2 Mg O 2 1 2

36. Balancing Equations Quick Check Fe3O4 + 4 H2 3 Fe +4H2O 1. Number of H atoms in 4 H2O a) 2 b) 4 c) 8 2. Number of O atoms in 4 H2O a) 2 b) 4 c) 8 3.Number of Fe atoms in Fe3O4 a) 1 b) 3 c) 4

37. Practice Balancing Equations Balance each equation. The coefficients for each equation are read from left to right What type of rxns are these? 1. Mg + N2  Mg3N2 a) 1, 3, 2 b) 3, 1, 2 c) 3, 1, 1 3 Mg + N2  Mg3N2 2. Al + Cl2  AlCl3 a) 3, 3, 2 b) 1, 3, 1 c) 2, 3, 2 2 Al + 3 Cl2  2 AlCl3 Synthesis- S Synthesis- S

38. What type of rxns are these? Fe2O3 + C  Fe + CO2 a) 2, 3, 2, 3 b) 2, 3, 4, 3 c) 1, 1, 2, 3 2 Fe2O3 + 3 C  4 Fe + 3 CO2 Al + FeO Fe + Al2O3 a) 2, 3, 3, 1 b) 2, 1, 1, 1 c) 3, 3, 3, 1 2 Al + 3 FeO 3 Fe + Al2O3 Al + H2SO4  Al2(SO4)3 + H2 a) 3, 2, 1, 2b) 2, 3, 1, 3 c) 2, 3, 2, 3 2 Al + 3 H2SO4  Al2(SO4)3 + 3 H2 Single Displacement- SD Single Displacement- SD Single Displacement- SD

39. Combustion of Hydrogen and Oxygen, which is a commonly used reaction in rocket engines: 2H2 + O2 → 2H2O 2, 1, 2 Burning of Propane C3H8 + 5O2 3CO2 + 4H2O 1, 5, 3, 4 Combustion reaction with Fluorine as an oxidizing agent: CH2S + 6F2 → CF4 + 2HF + SF6 1, 6, 1, 2, 1 Burning of Methane • CH4 + 2 O2 → CO2 + 2H2O 1, 2, 1, 2 Photosynthesis 6H2O + 6CO2 C6H12O6+ 6O2 6, 6, 1, 6

40. Homework- Pages 7: Balancing Chemical Equations & Types of Reactions • Work silently on this page. • It is for a grade!

41. List (2) possible observations that might make Angelina think she observed a physical change. No change occurs in the identity of the substance Color changes Size/Shape changes Phase changes (solid, liquid, or gas/condensation) List (9) possible observations that might make Angelina think she observed a chemical change. Atoms are rearranged to form different substances Bubbles of gas appear A precipitate (solid) forms A color change occurs The temperature changes Light is emitted A change in volume occurs Electrical conductivity change Melting/boiling point change Odor or taste change Bellwork: Friday 4/20/2012 Angelina performed two chemistry experiments in her science class. In the first experiment, she thought she observed a physical change. In the second experiment, she thought she observed a chemical change.

43. Chemistry Unit Test- Next Friday • Study Guide distributed on MONDAY • ACC: ~75 questions • Substitute Teacher

44. Silly Putty Chemistry • Adding Elmer’s School Glue to a water/Borax solution causes a chemical reaction to take place between • molecules of glue • Poly-vinyl acetate- C4H6O2 • molecules of Borax • Sodium borate- Na2B4O7 • This change produces a highly flexible, rubber-like material called a polymer—a lot like actual Silly Putty!

45. Page 9 • Silly Putty Chemistry • Mass of Reactants & Products • Bag- 1.45g • Bag, glue, water, borax, food coloring • Law of Conservation of Mass • Original Appearance of Reactants- color, state of matter • Glue, water, borax, food coloring • Formulas of Reactants • molecules of glue • Poly-vinyl acetate- C4H6O2 • molecules of Borax • Sodium borate- Na2B4O7

46. Silly Putty Chemistry • Background: Polymers are special molecules that form very long chains (picture strands of cooked spaghetti). • If the polymer chains slide past each other easily, then the substance acts like a liquid, because the molecules flow. • If the molecules hook together at a few places along the strand, then the substance behaves like a rubbery solid. • Polymers make compounds that are stronger and more flexible than other compounds. Examples of polymers are: rubber, latex, and nylon.

47. Silly Putty Chemistry • History: During World War II, the Japanese blocked the US from importing rubber. • The government asked the chemical industry to find a substitute. James Wright, an engineer, created a polymer from silicone and boric acid. • The pliable mass could be rolled up into a ball and bounced 25 percent better than a comparable rubber ball. • Unfortunately, the substance had some undesirable properties as well. When you hit it with a hammer, the stuff shattered; when you pulled it quickly, it broke apart.

48. Station 2: Silly Putty Chemistry Glue molecule (Poly-vinyl acetate) Cross-linking to form polymer: “Silly Putty” Borax molecule (Sodium Borate) Glue molecule (Poly-vinyl acetate)

49. Silly Putty Chemistry • Procedures: • Get a plastic bag and write your name on it with permanent marker. • Fill the small condiment cup 1/3 full with Elmer’s glue. • Fill the other 1/3 of the condiment cup with water. • Use the coffee stirring stick to stir well. • Pour the water-glue solution into the plastic ziploc bag • Add no more than 4 drops of food coloring into the bag. • Seal the bag and carefully knead for a 10-15 seconds until the food coloring is completely mixed into the water-glue solution.

50. Silly Putty Chemistry • Procedures: • Come get 1 tsp of supersaturated sodium borate solution into your bag. • Seal the bag then find the mass of the reactants by placing the bag on the electronic balance. • Seal the bag and carefully knead for a 10-15 seconds. Make and record your observations. • Remove the solid mass from the bag. Be sure to hold the mass over the bag for a few seconds to allow any liquid to drip back into the bag. • Reseal the bag and set it aside. Work the mass with your hands until it forms a “Silly Putty”-type solid. Experiment with this material and record your observations of its special properties. • Find the combined mass of the products by placing the bag with the remaining liquid, the “Silly Putty”-type solid, on the electronic scale. Record the mass. • Fill in the rest of the data table and answer the questions on page 12.