Monday, January 5, 2009

Jan 5th and 6th, Welcome to the new year!

Today in class we slipped back into our school routine after being away for 12+ days. Hopefully everyone had a good break and is ready to dig in to the schoolwork for these next few months.

Today we learned that our chapter three test will be this friday (January 9th) for all classes. Our homework due date has been moved up to Wed the 7th for the A day classes, Thur the 8th for the B day classes.

We received a study guide today--if you have lost it, head over to my website and check out the test and quizzes webpage for another copy of it.

In class we reviewed balancing chemical equations, the four clues that chemical reactions are occuring, and four different types of chemical reactions. We also went over the differences between chemical symbols, formulae and chemical equations and we talked again about the differences between exothermic and endothermic reactions.

Finally we started on section three. We demonstrated activation energy by dragging a match over a striker until it ignited, then we ignited some magnesium with a bunsen burner.

To end the class we looked at three factors that affect reaction rates: concentration of a solution, the starting temperature of a reaction and the surface area of the reactants. We cut a denture cleanser tablet in half, pulverized one half and then timed the amount of time required to dissolve the tablet and the powder in water. We then demonstrated the effect temperature had by dropping one tablet in room temperature water and another tablet in hot (almost boiling) water.

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