1. Honors Project By: Selena G. Lugo TEMPERATURE EFFECTS ON REACTION TIME

2. In this experiment I have used Alka-Seltzer tablets to test temperature effects on reaction time. The main ingredients in a tablet of Alka-Seltzer are Aspirin Citric Acid Sodium Bicarbonate (NaHCO3) Sodium Bicarbonate dissolves in water and splits apart into Sodium(Na+) & Bicarbonate (HCO3-) ions. The bicarbonate reacts with hydrogen ions (H+) in the citric acid which together form carbon dioxide and water.

3. Material Needed: 12 Alka-Seltzer Tablets Thermometer 300 ml beaker 1,000ml beaker ( use as Measuring cup) Masking Tape Hot & Cold Tap Water Ice Stopwatch Student Helper Notebook & Pencil Hot plate Stirring rod TEMPERATURE EFFECTS ON REACTION TIME

4. Step by Step….. (you will use the same 300ml beaker for all trials) Gather all materials for the experiment! Use the masking tape to label the desired water level (255ml) on the beaker Before you start set up the hot plate and begin to heat the water you will be using in the future steps (Cold tap water) Fill the beaker to the desired water level with cold tap water Check temperature of the water Proceed to drop the tablet in the water and time the reaction until its fully dissolved ( use stirring rod to make sure its fully dissolved)

5. TEMPERATURE EFFECTS ON REACTION TIME Record the time of reaction in your notebook Rinse the beaker and repeat these steps 3 more times using cold tap water ( make sure the initial temp. is always the same) (Ice cold tap water) Put some ice cubes in the beaker and fill it to the desire water level Check temperature of the water Once you have a set temperature remove the ice cubes Proceed to drop the tablet in the water and time the reaction until its fully dissolved ( use stirring rod to make sure its fully dissolved)

6. TEMPERATURE EFFECTS ON REACTION TIME Record the time of reaction in your notebook Rinse the beaker and repeat these steps 3 more times using ice cold tap water ( make sure the initial temp. is always the same) (Hot tap water) Fill the beaker to the desired water level with hot tap water Check temperature of the water Proceed to drop the tablet in the water and time the reaction until its fully dissolved ( use stirring rod to make sure its fully dissolved) Record the time of reaction in your notebook

7. TEMPERATURE EFFECTS ON REACTION TIME Trials1234 Cold Water (22 degrees Celsius) 59” 881’00”271’05”541’02”22 Ice Cold Water (7 degrees Celsius) 2’13”622’36”602’23”652’38”50 Hot Water (65 degrees Celsius) 25”5225”7920”9324”33

8. TEMPERATURE EFFECTS ON REACTION TIME

9. This experiment showed that in fact temperature does affect reaction time. As you can see in the chart above the cold water had a regular reaction. On the other hand the ice cold water had a very slow reaction while the hot water had a reaction in seconds. This tells us that the molecules in ice cold water do not provide the enough needed energy to produce a fast reaction such as the hot water did. This experiment showed that in fact temperature does affect reaction time. As you can see in the chart above the cold water had a regular reaction. On the other hand the ice cold water had a very slow reaction while the hot water had a reaction in seconds. This tells us that the molecules in ice cold water do not provide the enough needed energy to produce a fast reaction such as the hot water did.

10. TEMPERATURE EFFECTS ON REACTION TIME Cold tap water

11. TEMPERATURE EFFECTS ON REACTION TIME Ice Cold tap water Ice Cold tap water

12. TEMPERATURE EFFECTS ON REACTION TIME Hot tap water Hot tap water