Catalyst – February 2(11), 2011 HW OUT PLEASE! Label each of the following compounds/descriptions as either IONIC (I) or COVALENT (C). 1. NaBr 2. Low melting point 3. Good conductor, crystal 4. NO 2 5. Electrons shared

Today’s Agenda  Catalyst  Double Bubble Race  Multiple Covalent Bonds  Pause for Environmental Issues/Activist Letters…DHMO...Oh no!  Covalent Compounds: Naming and Formulas  Work Time  Progress Reports and Exit Question

Today’s Objectives  SWBAT compare/contract ionic and covalent compounds.  SWBAT draw Lewis Dot Structures for covalent compounds with multiple covalent bonds.  SWBAT name and write formulas for covalent compounds.

Double Bubble Group Race!  Each group will complete a Double Bubble Diagram…liiiiiike this (Double Bubble doc)  Rules: 1. No talking or sharing of notes! 2. First person fills in ONE bubble and passes paper to next person – cannot skip people! 3. If next person doesn’t know an answer, he/she must stand up and do a “I’m a Chemistry Stud” jump before passing paper. 4. Next person fills in ONE bubble and passes paper to next person…etc!

Multiple Covalent Bonds (Please get out yesterday’s AP worksheet)

LDS and Multiple Covalent Bonds Key Point #1: Sometimes atoms must share more than one pair of electrons in order to become stable.  This results in double and triple bonds.

Double and Triple Bonds  Double covalent bond: two pairs of shared electrons (four electrons)  Triple covalent bond: three pairs of shared electrons (six electrons) = =

Strengths of Bonds  Triple  Double  Single Key Point #2: Bond strength increases with number of bonds. So….a double bond is stronger than a single bond, and a triple bond is stronger than a single or double bond.

Example: Oxygen  Two oxygen atoms show up at the Spring Fling Dance. Each oxygen atom has $6, but it costs $8 per atom to go inside. The School of Elements is offering a discount for couples. It costs only $12 for a couple atoms to go inside. How can both atoms get inside if they each only have $6???  They can share…electrons that is!!!

Try this one: Nitrogen  Two nitrogen atoms show up at the Mardi Gras Party. Each nitrogen atom has $5, but it costs $8 per atom to go inside. The School of Elements is offering a discount for couples. It costs only $10 for a couple atoms to go inside. How can both atoms get inside if they each only have $5???  Model the bond formation of this happy couple!

Steps for Multiple Bond LDS’s 1. Write formula 2. Number of valence electrons (ve-) 3. Number of octet electrons (oe-) 4. Number of bonds 5. Draw!

More Examples O 2 CO 2 CO COCl 2

Try these!!! CS 2 NOBr Extra: SO 2 C 2 Br 6 Se 2 SiSBr 2

Practice Time! Worksheet….doooo it!

Politically Engaged Chemistry Studs…  Should learn the contents of basic chemistry…  Should also be able to understand the importance of chemistry in the environment…  There is a chemical, DHMO, that is especially ruining our environment in many ways… and something must be done.  You should have already letters to the government to help ban this awful, awful chemical  Anyone want to share his/her letter with the class?

Naming Covalent Compounds

Differences between ionic and covalent IONIC 2 ions come together! Metal + Nonmetal COVALENT No ions! Nonmetal + Nonmetal Examples: Na 1+ + O 2- CO 2

Naming Ionic and Covalent Compounds When naming compounds, you must know which rules to use (ionic or covalent).  Ionic: Metal + Nonmetal  Covalent: Nonmetal + Nonmetal

Yo Yo! Let’s 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

Naming Covalent Compounds Rule 1: If the first element has more than one atom, give it a prefix.

Naming Covalent Compounds 1 – mono-2 – di- 3 – tri-4 – tetra- 5 – penta-6 – hexa- 7 – hepta-8 – octa- 9 – nona-10 – deca-

Naming Covalent Compounds PCl 3

Naming Covalent Compounds PCl 3 Phosphorous

Naming Covalent Compounds Rule 2: The second element always gets a prefix, uses the root of the word and ends in - ide.

Naming Covalent Compounds PCl 3 Phosphorous

Naming Covalent Compounds PCl 3 Phosphorous Trichloride

Naming Covalent Compounds Rule 3: The “o” or “a” at the end of the prefix is dropped if the element begins in a vowel.

Naming Covalent Compounds N2ON2O

Rule 1: If the first element has more than one atom, give it a prefix.

Naming Covalent Compounds N 2 O Dinitrogen

Naming Covalent Compounds Rule 2: The second element always gets a prefix, uses the root of the word and ends in - ide.

Naming Covalent Compounds N 2 O Dinitrogen Monooxide

Naming Covalent Compounds Rule 3: The “o” or “a” at the end of the prefix is dropped if the element begins in a vowel.

Naming Covalent Compounds N 2 O Dinitrogen Monooxide

Naming Covalent Compounds N 2 O Dinitrogen Monoxide

Quick Examples! CCl 4 As 2 O

 What is the formula/name of the compound formed from lithium and oxygen atoms?  How do we know what rules to use when naming?  Decide if it is ionic or covalent FIRST!  Metals and non-metals make ionic compounds  Non-metals make covalent compounds Test Question Example 1

Naming Ionic Compounds LiO

Naming Ionic Compounds LiO Lithium Oxide

 What is the formula/name of the compound formed from nitrogen atom and hydrogen atoms?  How do we know what rules to use when naming?  Decide if it is ionic or covalent FIRST!  Metals and non-metals make ionic compounds  Non-metals make covalent compounds Test Question Example 2

Mixed Review of Naming NH 3

Mixed Review of Naming NH 3 Nitrogen Trihydride

MIXED REVIEW OF NAMING

Mixed Review of Naming CrCl 2

Mixed Review of Naming CrCl 2 Chromium (II) Chloride

PCl 3 Mixed Review of Naming

PCl 3 Phosphorus Trichloride Mixed Review of Naming

SF 6 Mixed Review of Naming

SF 6 Sulfur Hexafluoride Mixed Review of Naming

Al 2 O 3 Mixed Review of Naming

Al 2 O 3 Aluminum Oxide Mixed Review of Naming

WHITEBOARDS!

Whiteboards SO

Sulfur Monoxide

NO 2

Nitrogen Dioxide

N2ON2O

Dinitrogen Monoxide

P2O5P2O5

Diphosphorous Pentoxide

PCl 5

Phosphorous Pentachloride

NF 3

Nitrogen Trifluoride

Independent Practice Time  Lucky you!

On your own paper, write the names and formulas… First! Decide if it’s ionic or covalent! Turn in to folder! Write names 1. Na 2 O 2. CO 2 3. GeBr 4 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

Exit Question 1. Write the formula for:  Silicon dioxide  Dihydrogen monoxide 2. Write the name for the following compounds:  CO 2  NH 3