November 2008 Archives

Students were asked to review the proper balancing of equations using coefficients. Much more work will be done on this topic in the near future.

Homework was reviewed and corrected. Students were asked to correctly formulate the answers for #7-15 of the Word Equations WS given on Friday. Those answers are in the file below:

Word Equations.docx

After serious complications by a few students, I would strongly recommend that students review:
Naming Rules
Formula Rules
Oxidation Numbers
Polyatomic Ions

Using electronegativity to predict the types and strengths of bonds were introduced.
Polar and nonpolar covalent bonds were described and diagrammed, as were the rules governing the solubility of polar and nonpolar bonds to each other.
Students were to list and describe the three forces of attraction between covalent compounds, the properties of covalent compounds, and network compounds.

Homework was checked and answered. Students were verbally quizzed on whether or not they could name various compounds from the worksheets.
Using symbols to indicate the phases of substances in reactions were covered:
Solids (cr)
Liquids (l)
Gases (g)
Aqueous Solutions (aq)

As was the concept that the total mass of the reactants and the total mass of the products must be equal to each other.

Homework:
p. 637, # 1, 2 ,4, 6
p. 640, # 1, 2, 3, 4, 5, 6
p. 644, # 1, 2, 3, 6, 7

and this worksheet, asking students to correctly write the formulas from names...

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I've tried several times to upload the PPT version of the notes, but there seems to be some kind of internet problem. I'll try again tomorrow.

We continued balancing equations, and began classifying equations:
Synthesis
Decomposition
Single-Replacement (Single-Displacement) also called substitution reactions
Double-Replacement (Double-Displacement) also called metathesis reactions
Combustion
 We also listed properties for identifying Acids and Bases in Neutralization reactions...

Now these three worksheets are completable and due tomorrow, Friday, 11/21:
PSif61.bmp

We considered the concepts of exceptions to the Octet Rule (odd numbers of electrons, Suboctets, and Expanded Octets).
We began to reveal the rules to shaping molecules including the VSEPR theory and the rules for spd hybridization. A neat movie explaining hybridization is here...

At www.glencoe.com,

Choose your state,

Select student/parent

Subject science

Select the "ENTER" button

Select "Chemistry"

Choose "Chemistry: Matter and Change 2008"

Click "Click here to enter Student Center"

Click "Online Student Edition"

and again...

input the code, D68616EA49

and congratulations! That convoluted path leads you to the online textbook... Considering the large file sizes and possible slow download/display times, don't you think it would be easier to transport the book itself?

Students took their test on Bonding.

As a form of summative lab in order to prepare for their test tomorrow, students used wooden molecule sets to model, name, write the correct formula, and draw the lewis structures for ten molecules.

 

Bonding pairs.xls

A spreadsheet for figuring out the number of bonding pairs when drawing structural formulae.

We began the process of balancing equations by counting the numbers of atoms in a formula. We noted the exceptions for counting atoms in a formula that contains subscripts, parentheses, and coefficients.
Balancing a chemical equation has to to with using coefficients to multiply the number of atoms of a particular element on both sides (reactant and product) of a chemical equation.

We answered the homework, and then proceeded with naming compounds.

We discussed the ancient names that supercede modern nomenclature, such as ammonia instead of nitrogen trihydride.

Hydro- acid and oxy- acid naming conventions were covered, and students were asked to answer the questions 19-30 on page 251.

Students delved the mysteries of covalent bonds, including Lewis Structures, sigma and pi bonds, bond energy, bond dissociation energy, the differences between endothermic and exothermic reactions, and elementary covalent nomenclature.

The students were assigned the following homework problems:

p. 244, #1-6

p. 247, #8, 9, 10, 13

p, 248, #14-18

The homework was answered, and students were introduced to elementary chemical equations, including the three parts of a chemical equation:

reactants

products

yeild arrow

 

They were assigned a larger homework review due Thursday, 13 November:

pp. 626-629

1-10

11-18

20, 23, 24, 27, 29, 31, 32

An outline was created to review for the topics on the next major test on Friday, the 14th of November.

Students were asked to complete the following questions from their textbooks for homework:

p. 606, # 2, 5, 6

p. 614, # 2, 4, 6

p. 621, # 1, 2, 3, 4

Homework was reviewed, and students were asked to solve the four parts of #39 on p. 122.\

Students were then directed to construct a foldable of four parts:

Ionic Bonding (definition, <comprised of metals, nonmetals, and polyatomic ions>)

Covalent Bonding (definition, <comprised of metals, nonmetals, and polyatomic ions>)

Metallic Bonding (definition, <comprised of metals, nonmetals, and polyatomic ions>)

Alloys (definition, comparing substitutional and interstitial alloys)

This foldable is due tomorrow, 11/11

Students were asked to complete a vocabulary worksheet to help them focus after the Election Day Vacation.

PSKey Terms Chemical Bonds.bmp

They were introduced to hydrates, their naming and how to spot their formula.
They were given a small packet of review materials to begin their progress towards the next test.

After turning in their projects, students were reminded about the properties of ionic bonds and how important oxidation numbers are to forming ionic bonds. They were shown how to make binary compounds and to properly name them, including using Roman Numerals for Transition and Post-Transition metals.
Students were given a sheet to take home and practice their skills.

CHIonic Compounds.bmp

Students finished their time in class to work on their Performance Assessment.

Wednesday, after the PAs are turned in, we will begin discussing chemical bonding, including answering the questions:

• Why do atoms bond?
• What kinds of bonds do they form?
• Are there limits to how much of a compound can form?

Students continued to exercise their process skills by naming compounds in covalent bonds (using prefixes), compounds made from polyatomic ions (NOT changing the polyatomic ion's name), and using roman numerals to denote the oxidation number of metals in groups 3-12 and under the stair-step on the periodic table.

As a culminating activity, students were asked to name compounds of all kinds on one worksheet and to successfully write a chemical formula from just the name of the compound on another.

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