Name _______________________________________ ChemistryMr. Harper

CH 6: Bonding PacketStudy 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 bondinga. 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 bondinga. 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 compoundsa. 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?

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Bookwork

1. p.177 #1-62. p.196 #1-43. p.194 #1-54. p.199 #1 and p.201 #15. p.207 #2a&b,3,5,66. p.210 #25-28,30-32

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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:

5 substance samples10 test tubesBunsen burnerDistilled water5, 100 mL beakers

Battery3 alligator clipsLight bulb & socketTest tube rackTest tube holder & clamp

Support standCork stoppers5 Weigh boatsTriple beam balanceGraduated cylinder

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.

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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

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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

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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

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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

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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

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Intermolecular Forces

Dipole-dipole Hydrogen Bonding London Dispersion

1. 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

____________________.

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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:

Large filter papersPencil

6 BeakersWaterAssorted markers

ScissorsRulerRubbing alcohol

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:10

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.

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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

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Chemical Bonding Comparison

Characteristic or property Ionic MetallicCovalent

Molecular NetworkTypes 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.)

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