Unit 5: Bonding Part 2 (Covalent Bonds/Bond & Molecular Polarity/IMF)

Transcription

1 Unit 5: Bonding Part 2 (Covalent Bonds/Bond & Molecular ity/imf) The following pages are practice questions for this unit, and will be submitted for homework! You must complete: Ionic vs. Covalent Properties Chart ALL QUESTIONS Lewis Dot Structures of Molecular Compounds ALL QUESTIONS Polyatomic Ions What They are and How to Name Them ALL QUESTIONS Naming Covalent Compounds ALL QUESTIONS What Type of Bond ALL QUESTIONS Non- vs. vs. Ionic Review Chart ALL QUESTIONS Molecular ity ALL QUESTIONS Practice Regents Questions ALL QUESTIONS DUE: Friday December 8,

2 Ionic vs Covalent Properties Review Chart Directions: Fill in the chart below to review properties of ionic and covalent compounds. Go back to your notes to help. Bonded Name Bonding Type Types of Elements Physical State Melting Point Solubility Conductivity Ionic Covalent Molecular Formula Lewis Dot Structures of Molecular Compounds Dot Structure of Atoms Present Dot Structure of Molecule Structural Formula Types of Covalent Bonds CH4 HF I 2 CO 2 H 2 O 2

3 Polyatomic Ions What They are and How to Name Them Polyatomic ions. "poly" means many. Ions are particles with a positive or negative charge. So polyatomic ions are groups of (many) two or more atoms that have a charge. The group as a whole shares the charge. The polyatomic ion is treated just like the negative nonmetals we have been using already. Most polyatomic ion s names end in "-ate" some end in "-ite". Only a few end in "-ide". Most polyatomic ions are negative. 1. Look up the following polyatomic ions Write down the formula (including the charge): ammonium acetate carbonate dichromate hydroxide nitrate oxalate sulfate phosphate permanganate nitrite cyanide sulfite hydrogen carbonate 2. What is common about most of the names of the polyatomic ions? 3. What element do most of the polyatomic ions have in the formula? 4. What type of elements are found in the polyatomic ions? (metal/nonmetal) Naming ionics with polyatomic ions. Identify the compound as an ionic compound first [begins with a metal and ends with nonmetal(s)]. You have to recognize the polyatomic ions within the formula. At first you may incorrectly attempt to name every element in the formula. If the formula begins with a metal and ends with two or three nonmetals then it must be a polyatomic ion in the formula. Steps for naming: 1. Name the metal with its full name. 2. Identify the polyatomic ion at the end of the formula, use its name. Examples: Ca(NO3)2 Ca(NO 3 ) 2 calcium nitrate #C: #N: #O: KNO3 K NO 3 potassium nitrate #K: #N: #O: Ba(OH)2 Ba(OH) 2 barium hydroxide #Ba: #O: #H: Li2CO3 Li 2 CO 3 lithium carbonate #Li: #C: #O: Al2(SO4)3 Al 2 (SO 4 ) 3 aluminum sulfate #Al: #S: #O: NH 4 ClO 3 NH 4 ClO 3 ammonium chlorate #N: #H: #Cl: #O: 3

4 Practice: 5. Name the following: NaOH: NaC 2 H 3 O 2 : BaSO4: AlPO4: NaClO3: Ca(OH)2: ZnCO3: AgNO3: When writing the formulas for compounds with polyatomic ions from the names, you need to balance the charges just like you did before with binary (only two elements) ionic compounds. last worksheet When a polyatomic ion must be multiplied to make the compound neutral, parentheses must be used so that any subscripts added will apply to the entire polyatomic ion. examples: sodium carbonate calcium phosphate o sodium in compounds = Na + carbonate = CO3 2- o drop the sign and switch the charge number to be a subscript for the opposite ion: o Na 2 (CO3) parentheses around CO3 not needed since there is just one, do not write the subscript 1. o Na 2 CO 3 = final answer o calcium = Ca + phosphate = PO4 3- o Ca3 (PO4) distinguish between subscripts used for balancing charge and those that are part of the formula of the polyatomic ion by using parenthesis o Ca 3 (PO 4 ) 2 à final answer 6. Write the formulas for the following compounds and determine the number of each atom: sodium nitrate: potassium acetate: aluminum sulfate: potassium dichromate: ammonium sulfate: lithium chlorate: magnesium nitrate: ammonium acetate: sodium sulfate: potassium nitrate: 4

5 Name: Per: Date: Naming Covalent Compounds Directions: Name the following molecular compounds. 1. CO 2 : 6. PCl 3 : 2. SO 2 : 7. NH 3 : 3. N 2 O: 8. P 2 O 5 : 4. N 2 O 3 : 9. SiO 2 : 5. N 2 O 4 : 10. OF 2 : Directions: Write the formula for the following molecular compounds. 1. Carbon monoxide: 6. Phosphorus pentachloride: 2. Sulfur trioxide: 7. Sulfur hexachloride: 3. Nitrogen monoxide: 8. Carbon tetrachloride: 4. Nitrogen dioxide: 9. Carbon disulfide: 5. Dinitrogen pentoxide: 10. Phosphorus tribromide: What Type of Bond? Directions: Using the E.N.D., determine the type of bond present in each of the following bond pairs. 1. C-O: Carbon E.N. Oxygen E.N. E.N.D. Bond: 2. N-N: Nitrogen E.N. Nitrogen E.N. E.N.D. Bond: 3. N-H: Nitrogen E.N. Hydrogen E.N. E.N.D. Bond: 4. B-F: Boron E.N. Fluorine E.N. E.N.D. Bond: 5. C-H: Carbon E.N. Hydrogen E.N. E.N.D. Bond: Non- Covalent vs. Covalent vs. Ionic Review Chart Directions: Fill in the chart below to review the different types of bonds. Your chart must include the following topics: Type of elements involved E.N.D. What happens to the electrons An example Ionic Bond Covalent Bonds Covalent Non- Covalent 5

6 Name: Per: Date: Molecular ity Directions: Use the information below to determine is a molecule is polar or non-polar Determining Molecular ity 1. Drawing the molecular structure 2. Assigning the polarity of each of the bonds 3. Adding the bond dipoles to determine the net molecular dipole. 4. Deciding if the bond dipoles cancel. If they do cancel, the molecule is non-polar. Non- Non- Non- Non- 6