Exothermic-Endothermic Labs Make-up

1. Exothermic-Endothermic Labs Make-up

2. Exothermic Lab • Exothermic means energy is being released from the reaction into the surrounding air • Heat turns from chemical energy into heat energy. • Because there is now more heat than you started with, the temperature goes up! • A temperature change can be an indicator of a chemical reaction! • Take temperature readings every minute until the reaction is done.

3. 250 250 200 200 150 150 100 100 50 50 • On the thermometer, there • Are three types of lines: • Short black: 2.5 degrees • Long black: 5 degrees • Long blue: lower one is 0 degrees, • middle one is 50 degrees, • upper one is 100 degrees Now watch the temperature as we allow the Steel wool to react with the oxygen in the air. It may not look like much is happening but it Is! Keep a close eye on the temp as well as The steel wool. You will see changes! Keep taking temperature readings every min. While we are watching the control test, we will soak the steel wool in vinegar to remove the protective coating on the metal. This will allow it to react with the oxygen in the air. Steel Wool Bundle To start out, we will do a “control temperature test” to determine that the temp in the beaker is not already changing on it’s own. We do this by putting the thermometer in the beaker by itself for 1 minute. We watch this now: Vinegar Success! You can see that the temperature has risen as a result of the Reaction! This is an Exothermic Reaction!!! Also, you should see “rust” Has formed on the steel wool itself! Rust is an indicator of the reaction. Now that we can confirm that the temp is not already changing on its own in the beaker we know that any change in temp will be because of the reaction alone. Place the steel wool on the thermometer.

4. Endothermic Lab • Exothermic means energy is being released from the reaction into the surrounding air • Heat turns from chemical energy into heat energy. • Because there is now more heat than you started with, the temperature goes up! • A temperature change can be an indicator of a chemical reaction! • Take temperature readings every minute until the reaction is done.

5. 250 250 250 200 200 200 150 150 150 100 100 100 50 50 50 Baking Soda Sample • On the thermometer, there • Are three types of lines: • Short black: 2.5 degrees • Long black: 5 degrees • Long blue: lower one is 0 degrees, • middle one is 50 degrees, • upper one is 100 degrees First we will do a control temperature test. We need to know for sure that the temp is not already changing in the beaker. We will leave the thermometer in the vinegar for 1 minute and see if there is a change. If there is no change in the temperature, then we know that any change at all is due to the chemical reaction and not something else! There is an obvious reaction occurring here! The “fizz” is an indicator of the reaction. But if you watch the temperature, you will see it change as well! Now that our control temp test is completed. At this time we add the baking soda to the vinegar and observe the reaction and temp results. Now we will add the Baking Soda to the Vinegar and observe the reaction Vinegar in the beaker for control test Success! The fizzing and lowering of temperature are two Indicators of an endothermic reaction! Now finish your questions: