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LARN 064 C16D4

Start the following in class:

1.a.  Use the PQ5R or SQ5R method to prepare study guide for text section 8.3 on Bonding Theories or go to https://socratic.org/chemistry to research the topics brought up in section 8.3 of your text.  Read section 8.3 of your chemistry text on Bonding Theories, pages 230 through 236, and as you do, create a study guide using the SQ5R or PQ5R method explained in class and on the distributed handout packet. You may record vocabulary entries in the body of your study guide, or you may check them off on the chapter 8 vocabulary list as you think about the meanings of the terms and add any notations to the vocabulary list for clarifications sake.

2.b. Writing in blue or black ink, place your hand in number in a circle followed by your name in the upper right white space of a piece of three holed composition paper in your learning log that hasn’t been written on.  Place the page reference for the problems to be considered to the left of the red marginal line on the first blue line.  Centered on the first blue line, write a descriptive title for the learning activity such as Section [chapter #.section#] Responses.  Before you write your response to each question or problem listed below, write its designation to the left of the red marginal line as listed below, followed by your response in ink to the right of the marginal line.

  • In the Section Assessment 8.3 on page 236, read, analyze, and and answer questions I8-23, I8-24, I8-25, I8-26abc, I8-27, and construct dot/dash structures as part of your response for practice problems I8-28, and I8-29.
  • After you are finished, check page R88 of the text and check each of those problems that you can by writing in either a check mark (√) or a correction in green ink as we do in class.  Some questions do not have a suggested response given.  For each such question, circle the number of the question in the margin of your notebook paper and check your response with that of your classmates when you come to class.

2. In your Journal Notebook write your journal entry on sheets of three holed 8.5 inch by 11 inch ruled paper.  In the upper right corner white space of each upward facing page, use a blue or black pen to write your hand in number within a circle followed by your name.  To the left of the marginal line, print J64 and circle it. Each journal entry should either be at least a paragraph of exemplary writing and penmanship concerning a single topic, or be a concept map relating chemistry terms. Begin each day’s paragraph with a topic sentence, follow with explained instances, and close with a focused summary statement. The required journal focus question J64 for today is

a. The electron dot structure for methane, CH4, is represented entirely on the two dimensions of a writing surface and so the measure of the H-C-H angles in methane, CH4, appear to be 90°.  According to text Figure 8.16, what is the actual measure of the H-C-H angles in methane, CH4?

b. What is meant by the term, the tetrahedral angle?

c. What is the basic idea behind valence shell electron repulsion (VSEPR) theory?

d. What is the predicted approximate measure of each of the three angles in a trigonal planar molecule?

        e. According to the textbook, what causes the measure of the H-N-H angle in the ammonia molecule, NH3, to be less than the tetrahedral angle?

Recommended for those who have time left in their 45 minute study period, but not required of all:

1.  Construct dot formulas and dot/dash formulas for the first twelve (12) models in the packet of papers distributed for laboratory model building activity U05-5 (a.k.a. A28LA) entitled Three Dimensional Models of Covalent Molecules.  Use the total number of noble gas tendency electrons (TE), total number of valence electrons (VE), calculated number of shared electrons (bonding electrons) (SE), and calculated total number of nonbonding electrons (NBE) method of constructing dot formulas that was taught in class and is also explained on the handout entitled Guidelines for Drawing Lewis Structures for Covalently Bonded Atoms.

Using blue or black ink write in small print in the column on the left and show your calculation of the total number of tendency electrons,TE, your calculation of the total  number of valence electrons,VE, the calculated number of shared electrons, SE, and the calculated number of non-bonding electrons, NBE for a molecule of each substance. Then use the calculated quantities and with a pencil draw a small dot formula for a molecule of each substance in the column on the right. The dot formula needs to be small to fit neatly into the rather small box provided.

Again use blue or black ink to construct the structural dot/dash formula for a molecule of each substance in the column titled Structural Dot/Dash Formula.

Note: The atom chain for dot and dash/dot formulas of H3CCH3 is H-C-C-H and should be drawn in a tetrahedral-tetrahedral structure. Similarly, work out the structures for the following three molecules from the condensed formulas given and check online if you get stumped.