Unit 2: Chemical Reactions

Transcription

1 Unit 2: Chemical Reactions Title Oct 13 10:33 AM Chemistry Review Activity: 29 Brains are better than At your first station, brainstorm with your group and try to write down as much information about chemistry from Science 9 as you can (matter, atoms, elements, periodic table, safety, etc). When the timer goes off, stop and look to the front for directions. (15mins) 2. Move clockwise to the next station & bring your markers. Edit the info listed by the first group if needed, and add anything you feel is missing. When the timer goes off, stop and look to the front for directions. (10mins) 3. Move clockwise to the next station & bring your markers. Edit the info listed by the first two groups if needed, and add anything you feel is missing. When the timer goes off, stop and look to the front for directions. (5mins) 4. Move clockwise to the next station. We'll take turns sharing info and use it to make review notes together. I'll help you decide if each piece is important enough to write down. If a group shares something that you have on your chart paper too, put an X by it so we don't write it down twice. Chemistry Review Activity Throw down Showdown 1. Come up with a science themed team name. Write it at the top of your flip chart paper. 2. Brainstorm with your team write down anything and everything you can remember about the Atoms and Elements unit in Science 9 IN POINT FORM. Hide your work from the other teams!! 3. When the timer goes off, stop writing! Turn to face the front of the room. Keep one marker, and have one team member return the rest. 4. Taking turns, each team will offer one piece of information, while the other teams check their lists to see if they have the same idea written down. If you have something another team shares, put an X by it so you don't use that same fact again. 5. The only way your team scores a point is if you had something written down that no other team recorded! Review Activity 1 Review Activity 2 Monday, October 17th Chemical Compounds Octet Rule 3 Main Types Ions & Practice: p.189 #1 4 Gr 9 Review Quiz Tomorrow I expect you to practice & study Mon Oct 17 Periodic Table 1

2 Compounds 2+ different elements bonded in a fixed proportion Atoms want to have a complete valence shell (like the noble gases) They achieve this by sharing or transferring electrons: Ex: H 2O This is called the octet rule because most elements want 8 valence electrons. (Exceptions: Hydrogen and Helium only want 2). o Noble gases do not easily form compounds because their electron arrangements are already stable all by themselves. Compounds There are 3 main types of compounds: Elements: Electrons: Example: Molecular Compounds Elements: Electrons: Example: Metallic Compounds Elements: Electrons: Example: Octet Rule 3 Types of Compounds Atoms become ions when they transfer (gain/lose) valence electrons. ionic charge is the # value of the charge (+/ ). Write as a superscript on the right of the symbol (ex. Ba 2+ ). Families tend to form ions with similar charges. Look on the back of your Periodic Table! (Cation) Atom to Ion (Anion) Hydrogen fits on the left with the Alkali Metals because it has one valence electron that it can give away. Hydrogen also fits on the right with the Halogens because it could gain one more electron and have a full valence shell. Periodic Table of Ions Tuesday, October 18th Gr 9 Review Quiz > MUST be written in pencil > MUST be marked in pen Made up of a metal and a nonmetal Metals lose electrons & become positively charged (they are conductors, so they don't hold them well) Nonmetals gain electrons & become negatively charged (they are insulators, so they do hold them well) Practice: p.189 #1 4 Tues Oct 18 2

3 Ionic Bonding: oppositely charged ions are attracted to each other Result = electrically neutral compound p. 189 #1 4 Try it! Beryllium & chlorine (or Lewis Dot) Potassium & oxygen Ionic Bonding p. 189 #1 4 p. 189 # (a) How do metals form ionic compounds with nonmetals? (b) Describe the process with an example. p. 189 # Repeat question 2 for the compound formed by aluminum and fluorine. (a) Which element is the metal and which is the nonmetal? (b) Draw Bohr diagrams of aluminum and fluorine. 2. Beryllium and fluorine react to form an ionic compound. (a) Which element is the metal and which is the nonmetal? (b) Draw Bohr diagrams of beryllium and fluorine. (c) How many electrons must each element gain or lose to form stable ions? (d) Draw sketches to show how this compound forms by transfer of electrons. (c) How many electrons must each element gain or lose to form stable ions? (d) Draw sketches to show how this compound forms by transfer of electrons. (e) Indicate the ionic charges on the ions. (f) Which is the overall charge on the compound? (e) Indicate the ionic charges on the ions. (f) Which is the overall charge on the compound? (g) What is the chemical formula of the compound? 4. What part of the atom is involved in making chemical bonds? (g) What is the chemical formula of the compound? p. 189 #1 2 ANS p. 189 #3 4 ANS Monday, November 9th > Bonding > Naming > Formula Writing Practice: p.189 #1 4 Gr 9 Review Quiz Tomorrow > I expect you to practice & study NAMING Naming binary ionic compounds: Normal metal name, then nonmetal name ending in ide Tell you what elements are involved, but NOT how many of each NaCl sodium chloride CaF 2 calcium fluoride K 2O potassium oxide Mon Nov 9 Binary 3

4 Compounds A chemical formula is a combination of symbols that represent a particular compound. It indicates o what elements are present, and o the number of each atom present Formula Contains Name NaCl: Mg 2 Se: KF: Fe 3 C: sodium, chlorine magnesium, selenium potassium, fluorine iron, carbon Thursday, November 12th Chemical Formulas > Review > Short Cut > Practice p. 195 #1 6 Chemical Formula Thurs Nov 12 FORMULA WRITING o NOTE There are no spaces between symbols when writing chemical formulas. Be sure to capitalize the first letter of a chemical symbol. If there is a second letter, it is always lowercase. There is no need to write a subscript if there is only one atom of that element present. BaCl 2 Notes Nov 12 9:31 AM FORMULA WRITING 1. Temporarily write the ionic charge above each symbol. 2. Crisscross the ionic charges, using them as subscripts for the opposite ions. 3. Reduce the subscripts to the lowest numbers possible. Calcium Phosphide FORMULA WRITING Formula Writing Practice 4

5 Monday Oct 24th Recap Friday p. 195 #1 9 Return a ton of work p. 195 #1 9 Quiz Monday on Oct 24 p. 195 # Oct 24 11:02 AM 5

6 NAMING o o Some metals can form more than one kind of ion they are called polyvalent metals. Begin by writing the name of the metal and add a Roman numeral in round brackets after it to indicate its ionic charge. Finish with the name of the nonmetal ending in ide. Tuesday Oct 25th Practice Sheet Quiz Monday on Polyvalent Oct 25 Wednesday Oct 26th Polyatomic Ions Acids & Bases More Practice! Polyatomic Polyatomic ion: atoms that tend to stay together and carry an overall ionic charge (ex. Nitrate ion: NO 3 ). Find this table on your Periodic Table of Ions. Bond with metals to form a polyatomic ionic compound. Quiz Monday on Finish WHMIS Training TODAY! Oct 26 Polyatomic Polyatomic o When writing the formula of a polyatomic ionic compound, add brackets around the ion before showing the number you need. Ex. Ba(NO 3) 2 barium nitrate o Write the name of the metal first, then the polyatomic ion's name. All other rules for formula writing and naming still apply! p. 198 #1, 3, 4 1. In your own words, explain what is meant by "polyatomic ion." Give two examples. Fe(NO 3 ) 3 Fe(NO 3 ) 2 yttrium carbonate zinc phosphate 3. Write the formulas for the following compounds: (a) sodium phosphate (b) calcium sulfate (c) potassium chlorate (d) aluminum hydroxide (e) beryllium nitrate (f) magnesium hydrogen carbonate (g) nickel carbonate 4. Write the names for the following compounds: (a) K 2CO 3 (b) Na 2SO 4 (c) Al(HCO 3) 2 (d) AgNO 3 Polyatomic p. 198 #1 4 6

7 p. 198 #1, 3, 4 1. In your own words, explain what is meant by "polyatomic ion." Give two examples. 3. Write the formulas for the following compounds: (a) sodium phosphate (b) calcium sulfate (c) potassium chlorate (d) aluminum hydroxide (e) beryllium nitrate (f) magnesium hydrogen carbonate (g) nickel (II) carbonate 4. Write the names for the following compounds: (a) K2CO3 Acids Acids are special ionic compounds containing hydrogen. Hydrogen acts like the metal part of the compound (gives away its electron). Acids break apart into their ions in water. Naming acids hydrogen + nonmetal = hydro ic acid hydrogen + ate = ic acid hydrogen + ite = ous acid (b) Na2SO4 (c) Al(HCO3)2 (d) AgNO3 p. 198 #1 4 Acids Bases Bases are special ionic compounds containing the polyatomic ion hydroxide. Bases break apart into their ions in water. Bases have no special rules for naming just follow the normal instructions. Bases 7