Objective: Determine which reactions are endothermic and which ones are exothermic through observations and data.

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1 Grade 8: Standardized Task Competency Goal 4: The learner will conduct investigations and utilize technology and information systems to build an understanding of chemistry. Endothermic and Exothermic Reactions: An endothermic reaction is a reaction that requires energy to proceed. The intake of energy may be observed as a decrease in temperature as the reaction proceeds. Once the reaction is complete, the temperature of the mixture will return to room temperature. An exothermic reaction is a reaction that releases energy. During the reaction, a rise of temperature will be noted. Objective: Determine which reactions are endothermic and which ones are exothermic through observations and data. Procedure #1: 1. Pour two caps full of citric acid (lemon juice) into beaker. Place beaker in pan/bucket. 2. Use thermometer to determine temperature of citric acid. 3. Record temperature. 4. Measure out one tablespoon of sodium bicarbonate (baking soda) into a cup. Pour the sodium bicarbonate into the beaker of citric acid. Be ready to time quickly! 5. Record the temperature every 15 seconds for 2 minutes. 6. Wash out cup with water at sink. Data: Procedure #1 Temperature 0 sec. 15 secs. 30 secs. 45 secs. 60 secs. 1min. 15 secs 1min. 30 secs 1min. 45 secs 2 min. Graph for Procedure #1:

2 Procedure #2: 1. Place thermometer in the jar and close the lid. Allow 5 minutes for the thermometer to record the temperature, then open the lid and read the thermometer. 2. Remove the thermometer from the jar. 3. Soak a piece of steel wool (fine not course) in beaker of 50 ml of vinegar for 1minute. 4. Squeeze the excess vinegar out of the steel wool. 5. Wrap the wool around the thermometer and place the wool/thermometer in the jar, sealing the lid. 6. Allow 5 minutes, them read the temperature. Record. 7. Rinse and dry out all materials. Dispose of wool in trash. Data: Procedure #2 Before Activity After 5 minutes Temperature Conclusions: 1. What type of reaction was the first experiment? Endothermic or exothermic? How do you know? 2. What type of reaction was the second experiment? Endothermic or exothermic? How do you know?

3 Grade 8: Standardized Task Competency Goal 4: The learner will conduct investigations and utilize technology and information systems to build an understanding of chemistry. Students will research one of the following diseases/disorders associated with overexposure to toxic and/or nontoxic chemicals. cancer autoimmune disease birth defects heart disease diabetes learning and behavioral disorders kidney disease asthma The students need to research the chemicals that lead to these diseases/disorders and the potency, dose and exposures associated with the chemicals that cause these diseases/disorders. Students should then create a poster that describes 5 Things You Should Know About. See student handout for poster guidelines and rubric.

4 Name Date Disease / Disorder Awareness Poster Rubric Name of Disease or Disorder: Description of the disease or disorder with 3-5 with 1-2 but has no Chemical exposure associated with the disease or disorder exposure with 3-5 exposure with 1-2 exposure with no Potency and dose of the chemical potency and dose of the chemical with 3-5 potency and does with 1-2 potency and dose with no Treatment for the disease or disorder with 3-5 with 1-2 with no Reduction or elimination of exposure to the chemical ways to reduce or eliminate exposure with 3-5 ways to reduce or eliminate exposure with 1-2 ways to eliminate exposure with no Aesthetics of the poster Poster is neat, creative, and s graphics Poster is neat and creative with no graphics Poster is neat but not very creative Neither neat nor creative Total /18 = % Comments:

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