December 2008 Archives

Students received two study guides for the Midterm, which will occur at the end of next week. The one I constructed is here:
Physical Science Study Guide 2008.docx

We discussed the dissociation of ions and how that affects solubility in water, a polar molecule. We also reviewed soaps and detergents, polar on one end of their molecule and nonpolar on the other end of the molecule.

Students completed several exercises to demonstrate their ability to convert between atomic mass units, grams, and moles.

CHif49.bmp

The occurrence of a change in energy in any chemical reaction was related, and specifically a change in heat energy. Two forms of energy change were identified, endothermic and exothermic. The concept of activation energy was discussed, and the concepts of catalysts and inhibitors were introduced.

Homework was assigned:

p. 656-
#11-17, 19, 23, 26, 29, 30

The concept of the mole was introduced, as was the relationship between a mole of an element and its average atomic mass in grams.

Students reviewed acids and bases, and the pH scale was introduced. The use of indicators to determine the acidic or alkaline nature of substances was determined. Students then completed the first and easier worksheet:
PSif67.bmp
They were assigned the other pH worksheet for homework, due Monday:
ph_worksheet.doc

Students completed the "Marshmallow Lab", demonstrating the conservation of mass in a chemical reaction / equation.

Marshmallow lab.doc

Students participated in the Online EOCT CheckPoint test administered by the same corporation that makes and scores the End-of-Course-Test administered in May.
I have learned that parents do not have access to the data collected by this EOCT CheckPoint testing activity, so I will see about printing individualized reports for the parents and students.

One note, regardless of the imprudence: While this activity was a useful diagnostic tool for most of the students to assess their lack of comprehension of content material, the same small number of ignorant children who seem to perturb the learning environment on a daily basis were not only apathetic about this opportunity they were a near-continual source of disruption for the students who were working on this EOCT CheckPoint.

Students were asked to complete to following activity on reading solubility graphs:
Solubility Graph Worksheet.doc

While a few of the more recalcitrant students monopolized the classroom atmosphere, most of the students read the graph easily and completed the activity satisfactorily.

Homework was reviewed. Students were informed on how water, gases, and precipitates are clues to identifying double replacement reactions. Solubility and solution terms were reviewed, and Ionic and Net Ionic Equations were introduced.

Homework was reviewed, and students were asked to complete the following two worksheets:

CHif60.bmp

Solubility rules were discussed, including the definitions of solute and solvent. Standardization of comparable solubilities as well as the words "saturated", "unsaturated", and "supersaturated" were covered.
Examples of temperature affecting solubility included sweet tea served in "yankee" territory, gargling with salt water, and how rock candy is made from supersaturated solutions of sugar.

Here's the solubility curve:

Students were asked to demonstrate their understanding of balancing chemical equations by completing the "Balancing Chemical Equations" WS.
Students were then to demonstrate their abilities to write and balance chemical equations by using chemical and compound names to produce viable formulas and then balance the equations they write.
CHif59.bmp

A greater detail of solutions were covered, including the definitions of solute and solvent.

Aquaeous Solutions as typical examples were discussed, as were concentrations and the myriad of phases of which solutions can be comprised. The specific conditions to keep gases dissolved in a liquid solution were discussed, including how fish "breathe" and the fizz remains in sodapop until consumed.

The final topic was the three processes used to speed up the solution process and how they related to particle motion: Agitation, Temperature, and Surface Area.

Students were introduced to the concept that reactions can be classified according to the four major types of reactions: Synthesis, decomposition, single replacement, and double replacement. Categorization depends on the number and arrangement of particles in their reactants and products.

 Two additional classifications will also be covered tomorrow: Neutralization and Combustion reactions.