Name ______Chemistry
Mr. Harper
CH 6: Bonding Packet
Study Guide
1. What is a chemical bond?
a. Why do atoms form chemical bonds?
b. What is the octet rule and what role does it play in chemical bonding?
c. What are the four types of chemical bonds?
2. Ionic bonding
a. How do ionic bonds form? What types of elements form ionic bonds?
b. What is a formula unit?
c. How do you show the formation of an ionic bond using electron dot notation?
d. What are the properties of ionic compounds?
e. What is lattice energy?
f. What is the structure of ionic compounds and how does it explain their properties?
3. Metallic bonding
a. How does a metallic bond form? What types of elements form metallic bonds?
b. What is a sea of electrons?
c. What are the properties of metallic compounds?
d. What is enthalpy of vaporization?
e. What is the structure of metallic compounds and how does it explain their properties?
f. Why are the properties of a metallic compound different than an ionic compound if both form a crystal lattice?
4. Covalent bonding
a. How does a covalent bond form? What types of elements form covalent bonds?
b. What is bond energy?
c. Network
i. What are the properties of covalent network compounds?
ii. What is structure of covalent network compounds and how does it explain their properties?
d. Molecular
i. What is a molecule?
ii. What are the properties of covalent molecular compounds?
iii. What is structure of covalent molecular compounds and how does it explain their properties?
5. Molecular compounds
a. How do you draw the Lewis structure of a molecule?
b. How do you determine the geometry of a molecule? What is VSEPR theory?
c. How do you determine the polarity of a molecule?
d. What is the difference between polar and nonpolar covalent bonds?
e. What are the 3 intermolecular forces?
i. How do you determine the intermolecular forces of a molecular compound?
ii. How can you compare boiling points of substances based on the intermolecular forces?
Bookwork
1. p.177 #1-6
2. p.196 #1-4
3. p.194 #1-5
4. p.199 #1 and p.201 #1
5. p.207 #2a&b,3,5,6
6. p.210 #25-28,30-32
Bonding Lab
Purpose: To determine the type of bonding of a substance based on its properties.
Hypothesis: Make a prediction of the type of bonding for each substance to be tested.
Materials:
1
5 substance samples
10 test tubes
Bunsen burner
Distilled water
5, 100 mL beakers
Battery
3 alligator clips
Light bulb & socket
Test tube rack
Test tube holder & clamp
Support stand
Cork stoppers
5 Weigh boats
Triple beam balance
Graduated cylinder
1
Prelab:
1. Watch the teacher demonstration and record the results for the 4 types of bonding in the table below.
Substance / Type of Bonding / Elements Involved / Solid Conductivity Test / Melting point test / Water Solubility Test / Aqueous Conductivity TestCopper / Metallic / Metals
Table Salt / Ionic / Metal & Nonmetal
Sugar / Covalent molecular / Nonmetals
Amethyst / Covalent network / Nonmetals
Procedure:
1. Make a data table to record: (1) the substance being tested, (2) your prediction of the type of bonding, (3) result of the solid conductivity test, (4) result of the melting point test, (5) result of the water solubility test, (6) result of the aqueous conductivity test, (7) the type of bonding for each of the substances, and (8) the elements involved in the bond.
2. Predict the type of bonding for each unknown substance in the data table.
3. Place approximately 1 g samples of each substance into 5 weigh boats.
4. Touch both leads of your electrical circuit to each substance in the weigh boat. After each test, rinse the leads with distilled water and carefully dry them. Note your observation in the data table.
5. Place 5 test tubes in the test tube rack. Pour each sample from the weigh boats into the test tubes.
6. Secure the test tube clamp on the support stand and then light your Bunsen burner.
7. Place one of the test tubes in the clamp and heat it over the Bunsen burner flame. As soon as the substance melts, remove it from the flame. Do not heat any substance for more than 3 minutes. There may be substances that will not melt.
8. Note your observation in the data table and repeat for the other substances.
9. Place 5 more test tubes in the test tube rack. Put 0.5 g of each substance into its own test tube. Add 5 mL of distilled water to each test tube. Put a cork stopper on each test tube and shake it in an attempt to dissolve the substance. Note your observations.
10. Take the stopper off each test tube and pour the contents into separate 100 mL beakers. Immerse the leads of your electrical circuit into the contents of each beaker. After each test, rinse the leads with distilled water and carefully dry them. Note your observation in the data table.
11. Dispose of all substance samples in the waste beaker in the back of the room.
12. Clean all equipment with soap and water. Dry the equipment and return it to its proper place. Clean your lab station and wash your hands.
Analysis:
1. Using the control substances in the prelab, determine the type of bonding for each substance. Place your answer in the data table.
2. Using your book or the internet, look up the type of elements each substance is composed of: metals, nonmetals, or metalloids, and record this information in the data table.
3. Why was it necessary to rinse the leads after each test?
4. Why was it necessary to use distilled water in the experiment?
5. Do all compounds of a specific type of bonding have the same properties or can the properties vary? If so, give an example?
6. What are some other ways, properties, or characteristics that you could use to determine the type of bonding in a substance?
Conclusion:
Think about the properties of each type of bonding that you observed and explain why they have the properties that they have. Speculate on the chemical structure of their bonds that would give them the properties that you observed.
Lab Report:
· Name of Lab
· Names of Group Members (Yours at the top of the list)
· Period #
· Date
· Lab Purpose
· Data Table
· 2-3 Sources of Error (What affected your ability to make accurate observations?)
· Analysis (Answer questions 2-6 in the analysis section.)
· Conclusion
Electron Dot Diagrams for Ionic Compounds
Directions: Show the formation of the ionic bond between each of the following elements. Then, write the chemical formula.
1. Lithium and nitrogen
2. Sodium and oxygen
3. Potassium and fluorine
4. Beryllium and phosphorus
5. Magnesium and sulfur
6. Calcium and fluorine
7. Aluminum and nitrogen
8. Gallium and oxygen
9. Indium and fluorine
10. Strontium and sulfur
Lewis Structures 1
Draw the Lewis structures for the following molecular compounds using the procedure below.
1. Add up the total number of valence electrons.
2. Put the element that needs the most electrons in the center.
3. Give that element an octet of electrons.
4. Place the other elements around the central atom at pairs of electrons.
5. Fill in the rest of the electrons trying to get an octet around each atom.
6. If this is not possible, try double or triple bonds between atoms.
7. Count the number of electrons in the Lewis structure to be sure you have the right amount.
8. Turn all shared pairs of electrons into dashes to represent covalent bonds.
Compounds:
1. CH4
2. Br2
3. NF3
4. HCl
5. H2Se
6. ICl
7. CF4
8. PCl3
9. CF3I
10. Br2O
11. CS2
Lewis Structures 2: Multiple Bonds
Draw the Lewis structures for the following molecular compounds.
1. H2
2. O2
3. CO2
4. CH3I
5. NH2Cl
6. N2
7. C2H4
8. CH2O
9. ONCl
10. C2HBr
Molecular Geometry Worksheet (VSEPR Theory)
Molecule / Lewis Structure / # of e- pairs / groups around the central atom / # of atoms bonded to the central atom / Molecular Shape (Use the VSEPR theory to build the model of the molecule. Then, draw it.) / Geometry (Name of molecular shape. Use p. 200 in the textbook.) / New example (Give the formula of another molecule with same shape.)SiH4
PF3
H2S
CH2O
SPI
CO2
PCl5
SF6
1
Intermolecular Forces
Dipole-dipole / Hydrogen Bonding / London Dispersion1. Attraction between dipoles of ______molecules
2. A ______is a distribution of charge where opposite charges are on opposite sides of a molecule or atom
3. Happen between ______molecules
4. Effective only over a ______range
5. Always present for ______molecules; may be induced in ______molecules or atoms
6. ______of a molecule is determined from molecular geometry and type of covalent bond: polar or non-polar. / 1. ______type of ______-______force
2. Happens when ______is bonded to a highly ______element, such as ______, _____, & _____
3. Exposes hydrogen’s ______on one side of the molecule, making the molecule highly ______
4. Reason for surface ______of water and unusually high ______points of three compounds: ______, ______, & ______/ 1. ______intermolecular force
2. Exists in any atom or molecule regardless of ______
3. Happens because electrons are in constant ______
4. At times, there is an ______distribution of ______around the atom or molecule.
5. This distribution causes a ______dipole to form which results in the attraction between two ______.
6. When two neighboring molecules form these dipoles they ______each other, but the attraction only lasts for an ______.
1
Paper Chromatography Lab
Purpose: To see the difference between polar and nonpolar substances.
Hypothesis: Predict which color dyes are in a black marker (ex. red, blue, yellow, etc.).
Materials:
1
Large filter papers
Pencil
6 Beakers
Water
Assorted markers
Scissors
Ruler
Rubbing alcohol
1
Procedure:
1. Cut large filter paper circles into 6 strips approximately 1’’ x 4’’.
2. Measure 1’’ from the bottom of each strip and make a horizontal PENCIL line with an X in the middle.
3. Put a dot of marker on the X for each strip. Use a black permanent marker, a black washable marker, and 4 others of your choosing.
4. Place each paper strip in a beaker with a small amount of warm water in the bottom so that the paper is wet but the ink dot is not touching the water. You may want to crease the paper over the edge of the beaker so that it stays upright.
5. Let the water travel up the paper until it nearly reaches the top.
6. Record your observations:
7. Repeat steps 1-6 using cold water instead.
8. Record your observations with the cold water:
9. Repeat steps 1-6 using rubbing alcohol instead.
10. Record your observations with the rubbing alcohol:
Analysis:
1. Describe the colors found in each marker. List the color of the marker as well as the colors that made it up. Did any of these surprise you?
2. Compare the separations for the warm water, cold water, and rubbing alcohol. Was there any difference? Explain.
3. Which type of marker is most polar: permanent or water soluble? How do you know?
4. Which color dye is most polar? Which color dye is most nonpolar? How do you know this?
5. We have learned that water is a polar molecule. From the results of this lab, what polarity would you predict for rubbing alcohol? Explain your reasoning.
6. Why does the water travel up the filter paper and defy gravity? (Hint: Google “capillary action.”)
7. Think about why separating compounds based on polarity and intermolecular forces might be useful. List at least 2 ways that it can be useful.
1
Polarity Worksheet
Molecule / Lewis Structure / Molecular Geometry(Build the model so you can visualize it.) / Is the molecule symmetrical?
(Yes or No) / What kind of bonds does it contain, polar, non-polar, or both? / Is the molecule as a whole polar or non-polar? / What intermolecular forces apply?
(Dipole-dipole, Hydrogen bonding, London dispersion) / State of matter at room temp. (solid, liquid, or gas)? List the boiling point. See p.204.
CH4
NH3
H2O
CO2
N2
HF
1
Chemical Bonding Comparison
Characteristic or property / Ionic / Metallic / CovalentMolecular / Network
Types of elements in the bond (metals, nonmetals, metalloids)
Basic unit of compound (molecule, formula unit, atom)
Components of compound (atoms, shared electrons, cations, anions, sea of e-)
Structure of compound (crystal lattice or individual molecules)
Behavior of electrons (shared, free, transferred)
Measurement of bond strength (lattice energy, enthalpy of vaporization, bond energy)
Relative melting point (high, low, medium)
Typical water solubility (Yes, No, Depends on polarity)
Solid conductivity
(Yes, No)
Aqueous conductivity
(Yes, No, N/A)
Other properties: (e.g. Hard, brittle, malleable, ductile, weak intermolecular forces)
Example: Name and chemical formula
Model: Draw a representation of each compound. (Use back of sheet if necessary.)
1