Mole concept tips - Journal of Chemical Education (ACS Publications)

Dec 1, 1976 - Mole concept tips. J. Dudley Herron. J. Chem. Educ. , 1976, 53 (12), ... Fang, Hart, and Clarke. 2014 91 (3), pp 351–356. Abstract: Th...
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In the competition, two types of questions are asked; toas-up and honus. All toss-up questions are worth 10 points and honus questions are worth 10-30 points, depending on difficulty. Play is initiated by reading a toss-up question which students have 10 sec to answer. A student on either team may signal that he wants to answer the question by raising his hand. The oanel of . iudaes .. decides who responded first. If the student recognized answers the question correctly, his team scores and in given a bonus question. If the student answers incorrectly, the option to answer the toss-up question goes to the other team. If neither team answers the toss-up question correctly, the question is discarded and a new toss-up question is read. Bonus questions are read when a toss-up question has been answered correctly and may he answered only by the team that earned the right to the question. Team members may confer with one another hefore answering a honus question. If a honus question is answered incorrectly, the question is discarded and play proceeds with the reading of a new toss-UDauestion. I t req;ired a great deal of preparation on my part to gather auestions and olace ooint values on them. I relied heavily on supplemental workbooks, texts and old tests. Toss-up questions were primarily over definitions hut honus questions called for explanations, problem solving, writing formulas, or identification of substances. My higgest worry was that those wh~,were not competing would become hored and disruptive but this did not happen. Students became involved in the competition and even wanted to continue the game after the final match was finished. The game proved t o he fun for the students and gave me a very good indication of what they had learned in the course.

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hearts, in the rear pockets of their jeans, and under their pillows at night to remind them that the mole is a t the very heart of chemistry. a m Molecular Weight

22.4 liters

(if a gas at

S.T.P.)

-

particles

Richard Slade. White Bear Mariner Hieh School in White ~ e & Lake, MN &triangles and squares remind students of important equivalence relations involving the mole. Mr. Slade first uses an equilateral triangle using water as an examole to illustrate the relationshio between number of moles, number of molecules, and formula weight.

formula weight = 18 g After molar volumes of gases are introduced, Mr. Slade tells students to construct a square like the one below. In both diagrams, quantities listed on the equal sides of the figure are equivalent. This equality is emphasized by the arrows shown in the diagram 6x

loz3molecules H

Mole Concept Tips The Novemher, 1975 High School Forum dealing with the mole concept has resulted in two additional suggestions for helping students remember important relationships. Frederica Friedman, Science Coordinator a t The Brandeis School in Lawrence, New York advises students to keep the following diagram on pieces of paper in pockets over their

2 grams H,

Volume 53,Number

12, December 1976 / 7(H