Presentation is loading. Please wait.

Presentation is loading. Please wait.

Catalyst – February (72-46)/2, 2011 WAY BACK WEDNESDAY! HW OUT! 1. What is the mass of an atom that has 14 protons and 15 neutrons? 2. The reaction of.

Similar presentations


Presentation on theme: "Catalyst – February (72-46)/2, 2011 WAY BACK WEDNESDAY! HW OUT! 1. What is the mass of an atom that has 14 protons and 15 neutrons? 2. The reaction of."— Presentation transcript:

1

2 Catalyst – February (72-46)/2, 2011 WAY BACK WEDNESDAY! HW OUT! 1. What is the mass of an atom that has 14 protons and 15 neutrons? 2. The reaction of baking soda and vinegar at 25 degrees Celsius produces gaseous carbon dioxide for 1 minute. Which of the following do you think will happen if you react baking soda and vinegar at 50 degrees Cesius? a) Less gas will be produced b) Gas will be produced for more than 1 minute c) The reaction will have a strong odor d) The reaction will not occur

3 Todays Agenda Catalyst Review Naming and Formulas Electronegativity Difference, Bond Type, and Bond Polarity Review = Time to WORK Exit Question

4 Todays Objectives SWBAT name ionic and covalent compounds using CORRECT rules. SWBAT determine bond type (ionic or covalent) using electronegativity differences (EN). SWBAT get ready to DOMINATE both phases of the Unit 3 Test!

5 REVIEW OF NAMING & FORMULAS!

6 Yo Yo! Lets break it down! IONIC Metal + Nonmetal Writing Formulas: Kriss Kross charges Naming: 2 nd element ends in – ide, ignore subscripts COVALENT Nonmetal + Nonmetal Writing Formulas: Prefixes = subscript #s Naming: Use prefixes, 2 nd element ends in -ide

7 How do we know if this is a covalent compound? Is it between a metal and a non-metal? YES!!! Then, it is ionic!!! Is it between a non-metal and a non- metal? YES!!! Then, it is covalent!

8 A compound made from Lithium and Oxygen How do we know if it is ionic or covalent? Metals and non-metals make ionic compounds Naming Ionic Compounds

9 Ionic Bond Cation: Li Anion: O LiO

10 Ionic Bond Cation: Li Anion: O Li + O 2-

11 Ionic Bond Li + O 2- Cation: Li Anion: O

12 Ionic Bond Cation: Li Anion: O Li 2 O

13 MgO

14 Naming Ionic Compounds MgO Magnesium Oxide

15 NBr 3

16 Naming Covalent Compounds NBr 3 Nitrogen tribromide

17 Write the names and formulas… First! Decide if its ionic or covalent! Write names 1. Na 2 O 2. CO 2 3. CaBr 4. Na 2 CO 3 5. Mg 3 P 2 6. K 2 S 7. N 2 S 3 Write formulas 1. Carbon monoxide 2. Barium nitrate 3. Xenon difluoride 4. Carbon tetrachloride 5. Sodium carbonate 6. Lithium fluoride 7. Nitrogen trifluoride

18 How to tell ionic and covalent apart We can look at the formula: Ask yourself: Is it a metal and nonmetal or nonmetal and nonmetal? Key Point #1: Along with looking at the formula, we can also look at electronegativity differences (EN) in to determine bond type (ionic or covalent).

19 Electronegativity Differences We can also look at electronegativity differences (EN) Look at Electronegativity Chart to find element electronegativities Find the difference by using subtraction Look at Bond Type Chart to determine bond types Electronegativity Chart

20 Remember… Electronegativity is an atoms ability to attract electrons to itself in a chemical bond Electronegativity is expressed in numerical values of 4.0 or less These numerical values are called Paulings Higher number means the atom will attract electrons more strongly

21 Electronegativity Chart Pauling Values

22 Bond Polarity Key Point #2: Bond polarity is based on differences in electronegativities of atoms forming a bond As electronegativity difference (EN) increases, polarity of bond increases

23 Bond Polarity Terms to Know Pure Ionic = Complete transfer of electrons from one atom to another Polar Covalent = Unequal sharing of electrons between two atoms Nonpolar Covalent = Equal sharing of electrons between two atoms

24 Pure Ionic Bonding Total give and take (transfer) of electrons! = Big EN! I have no chance!

25 Covalent Bonding is like a Tug-of-War The more electronegative atom will pull electrons harder

26 Polarity and Electronegativity Polar Covalent - electrons are pulled more toward one of the atoms Big EN! Nonpolar Covalent - electrons are shared equally between atoms Low EN! Big Dog – Little DogMedium Dog – Medium Dog

27 Polarity Ranges Key Point #3: Bonds are not purely ionic (I) or purely covalent (NPC). They could be slightly ionic (VPC) or slightly covalent (MPC).

28 How to Calculate Electronegativity Difference (EN) 1. Using Electronegativity Chart, find Pauling values for each element 2. Subtract the smaller number from the bigger number Example: 4.0 (F) – 0.9 (Na) = 3.1 3. Look at Bond Type Chart to determine bond polarity

29 Bond Type Chart – Copy into notes! DEN RangeBond Type 0.0 – 0.39Nonpolar Covalent 0.4 – 0.89Moderately Polar Covalent 0.9 – 1.69Very Polar Covalent 1.7 or greaterIonic

30 Example 1 Determine the type of bond in LiBr 1. Find electronegativity of each atom

31 Electronegativity Chart

32 Example 1 Determine the type of bond in LiBr 1. Find electronegativity of each atom Li = 1.0 Paulings, Br = 3.0 Paulings

33 Example 1 Determine the type of bond in LiBr 1. Find electronegativity of each atom Li = 1.0 Paulings, Br = 3.0 Paulings 2. Find Electronegativity Difference (EN) DEN = 3.0 – 1.0 = 2.0 3. Look at chart to determine bond type.

34 Bond Type Chart DEN RangeBond Type 0.0 – 0.3Nonpolar Covalent 0.4 – 0.9Moderately Polar Covalent 0.9 – 1.69Very Polar Covalent 1.7 or greaterIonic

35 Example 2 Determine the type of bond in LiBr 1. Find electronegativity of each atom Li = 1.0 Paulings, Br = 3.0 Paulings 2. Find Electronegativity Difference (EN) DEN = 3.0 – 1.0 = 2.0 3. Look at chart to determine bond type. Bond Type: Ionic

36 Example 2 Determine the type of bond in O 2 1. Find electronegativity of each atom

37 Electronegativity Chart

38 Example 2 Determine the type of bond in O 2 1. Find electronegativity of each atom O = 3.4 Paulings, O = 3.4 Paulings

39 Example 2 Determine the type of bond in O 2 1. Find electronegativity of each atom O = 3.4 Paulings, O = 3.4 Paulings 2. Find Electronegativity Difference (EN) DEN = 3.4 – 3.4 = 0 3. Look at chart to determine bond type.

40 Bond Type Chart DEN RangeBond Type 0.0 – 0.3Nonpolar Covalent 0.4 – 0.9Moderately Polar Covalent 0.9 – 1.69Very Polar Covalent 1.7 or greaterIonic

41 Example 2 Determine the type of bond in O 2 1. Find electronegativity of each atom O = 3.4 Paulings, O = 3.4 Paulings 2. Find Electronegativity Difference (EN) DEN = 3.4 – 3.4 = 0 3. Look at chart to determine bond type. Bond Type: Nonpolar Covalent

42 How Polar Is It? Determine the polarity of each bond in the following compounds by calculating the electronegativity difference for each: 1. CO4. HF 2. AlP5. CaO 3. N 2 6. H 2

43 Electronegativity Chart

44 Bond Type Chart RangeBond Type 0.0 – 0.3Nonpolar Covalent 0.4 – 0.9Moderately Polar Covalent 0.9 – 1.69Very Polar Covalent 1.7 or greaterIonic

45 Practice Time! Please finish the worksheet Then, you can work on the Unit 3 Review Sheet U3T Phase I Tomorrow! U3T Phase II on Friday!

46 Exit Question Magnesium is a metal. Sulfur is a nonmetal. What type of bond is formed between these elements? Describe two ways that you could use to determine your answer to number 1.


Download ppt "Catalyst – February (72-46)/2, 2011 WAY BACK WEDNESDAY! HW OUT! 1. What is the mass of an atom that has 14 protons and 15 neutrons? 2. The reaction of."

Similar presentations


Ads by Google