Activity pubs.acs.org/jchemeduc
CHEMCompete: An Organic Chemistry Card Game To Differentiate between Substitution and Elimination Reactions of Alkyl Halides Kristin Gogal,† William Heuett,‡ and Deana Jaber*,† †
Department of Biology and Physical Sciences and ‡Department of Mathematics, Marymount University, Arlington, Virginia 22207, United States S Supporting Information *
ABSTRACT: Understanding substitution and elimination reactions is a critically important key to comprehending chemical reactions and their mechanisms. Memorizing differences between these reactions is one of the most commonly used strategies to learn this subject. A card game is a helpful supplement to teaching substitution and elimination reactions. A new organic chemistry card game, CHEMCompete, is presented that helps students predict the products of substitution and elimination reactions of alkyl halides and classify the types of these reactions. This game encourages cooperative learning in an enjoyable setting. Significant improvements were observed in both students’ self-rated survey responses and quiz scores evaluating their understanding of this topic. CHEMCompete is an effective study tool for learning substitution and elimination reactions of alkyl halides. KEYWORDS: Second-Year Undergraduate, Organic Chemistry, Collaborative/Cooperative Learning, Elimination Reactions
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teach concepts of general and organic chemistry.4 The organic chemistry games can be divided into four categories: puzzle games,5 card games,6 board games,7 and electronic games.8 Card games have been used for teaching purposes and have reported successful pedagogical results.4 Multiple card games have been developed for organic chemistry concepts, but there are no published records of card games specifically designed to help students differentiate between substitution and elimination reactions. Our aim was to design a new card game for substitution and elimination reactions of alkyl halides, which we have called CHEMCompete. The goal of CHEMCompete is to provide students with a study aid to (1) predict the product of the reaction and (2) classify the reaction as SN1, SN2, E1, E2 or a combination of these types of reactions.
INTRODUCTION Differentiating between substitution (SN1 and SN2) and elimination (E1 and E2) reactions is a difficult concept for students of organic chemistry to grasp. These reactions are foundational for understanding many chemical reactions. It is crucial that students learn and understand these reactions, the mechanisms through which they occur, and their contributing factors. Traditional chemistry education focuses on conveying chemistry knowledge via lectures and recitations.1 For learning to be most effective, there are expectations of both the student and the instructor. The former must dedicate time and effort, while the latter must deliver the content using methods that incorporate a variety of teaching strategies. One of the main pitfalls for students in organic chemistry is rote memorization, which leads to a superficial understanding of concepts.2 Incorporating pedagogical methodologies to engage students in interactive, enjoyable cooperative learning that promotes critical thinking is a novel and supplemental method of instruction.3 Chemistry educational games are promising solutions to remedy superficial teaching techniques and have been used to © XXXX American Chemical Society and Division of Chemical Education, Inc.
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MATERIALS
The cards necessary to play the game along with the handouts that were provided to the students are included in the Received: October 5, 2016 Revised: May 10, 2017
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DOI: 10.1021/acs.jchemed.6b00744 J. Chem. Educ. XXXX, XXX, XXX−XXX
Journal of Chemical Education
Activity
Figure 1. The first row represents the draw piles. The second row represents an example of a reaction sequence and how changing one card (in this case, adding heat) can change the outcome of the final product.
maximum of three reaction sequences can be in progress at any time. Each team has the option to trade one card per turn, exchanging one card of the same type from the respective draw pile. The team that plays the reaction arrow has to play a product card and a reaction-type card simultaneously. This team has a chance to win the reaction if it correctly predicts the product and classifies the reaction. In order to win the reaction, the team also has to defend its reasoning to the other team (preferably by drawing the mechanism). If the other team catches a mistake in the opponent’s defense, it can attempt to steal the reaction sequence by correcting the mistake. The team that wins a sequence must start a new sequence on its next turn. The game ends when a team completes five reaction sequences. The game duration varies, but typical game lengths observed were 15−20 minutes.
Supporting Information. The cards can be printed, preferably on cardstock, and cut out for use in the classroom. A flowchart depicting possible reaction sequences was designed and used while playing the card game. CHEMCompete is a card game that consists of a 96-card deck and can be played by 2−10 players. Rules
The 96 cards are distributed in six categories: starting material (18 cards), nucleophile/base (18 cards), solvent (17 cards), arrow (15 cards), product (10 cards), and reaction type (18 cards). The description of each type of card is detailed below: Starting Material. These cards are examples of primary, secondary, and tertiary alkyl halides. There are six cards for each type of starting material. Nucleophile/Base. These cards are examples of strong and weak nucleophiles/bases. Solvent. These cards are examples of protic and aprotic solvents. There are six protic solvent cards and 11 aprotic solvent cards. Arrow. These cards are double-sided so that students can choose to use heat in the reaction or not. The symbol Δ indicates the presence of heat, and the absence of that symbol indicates the absence of heat. Product. This card is a blank card and is filled in by the student. Students are expected to draw the final product structure. Reaction Type. These cards allow students to classify reactions as SN1, SN2, E1, E2, SN1/E1, or SN2/E2. There are three cards of each reaction type, except for the E2 reaction type, which has six cards.
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RESULTS AND DISCUSSION The 46 participants in the card game were students enrolled in an introductory organic chemistry course in the fall of 2015 who had received two lectures on substitution and elimination reactions of alkyl halides delivered by one faculty member. Upon completion of these lectures, students attended one of three consecutive workshops to play the card game. There were 14−16 students in every workshop session. In the workshop, the students (1) completed a consent form authorizing use of their data in this study, (2) completed a preactivity survey, (3) completed a preactivity quiz, (4) played the game for approximately 1 hour, (5) completed a postactivity survey, and (6) completed a postactivity quiz that was identical to the preactivity quiz. The Supporting Information includes copies of all of the assessment documents that were used in the workshops. All of the statistical analyses were performed using RStudio to run the statistical software package R version 3.1.2. Significance tests were conducted with a significance level of 0.05. Repeatedmeasures t-tests were performed for equality of variances and for equality of means for quiz scores, and Bhapkar tests were
Playing the Game
The game was played in groups of four players split into teams of two players each. Each player has four cards at all times; a starting material, nucleophile/base, solvent, and reaction type card. At the start of the game the dealer deals one of each of these four card types from their respective stacks to each player. The arrow cards and product cards are in two respective draw piles that players can draw during the game. The cards are played in order as shown in Figure 1. Teams alternate turns, with each playing one card per turn (either continuing a sequence already on the table or beginning a new reaction). A B
DOI: 10.1021/acs.jchemed.6b00744 J. Chem. Educ. XXXX, XXX, XXX−XXX
Journal of Chemical Education
Activity
still statistically significant. Quiz scores appeared to confirm and validate students’ self-rated performance. The survey data indicated a more significant difference in students’ abilities to predict the product before and after the card game was played than their ability to differentiate between and classify the type of reaction. The average quiz score for students’ classification of reactions increased about one point, from a preactivity average of 2.42 to a postactivity average of 3.67 (t = −4.15, d.f. = 45, p
