Observation: When I exercise, I sweat, I breathe heavily, I get warmer, my face turns red, my heart beats faster…hmmm? Hypothesis: “What are the effects of exercise on metabolism?” Prediction: Gather Data: Safety: 0.1 M NaOH is caustic. Avoid contact with skin. Use of of goggles mandatory. Flush contacted skin with soap and water. Bases feel “slippery”. Avoid drinking bromothymol blue Procedure: Pour 100 mL of bromothymol blue solution into a clean Erlenmeyer flask. Make a data table and record original color

Exhale breath through 3 drinking straws into bromo- thymol blue solution for 1 minute. Record color. Titrate color of solution back to original color by adding drops of 0.1 M NaOH solution. Record the number of drops. Dump out solution and rinse flask, then refill the flask with 100 mL of fresh bromothymol blue solution. Exercise for 1 minute (either sit-ups or running). Without resting, immediately exhale breath through same drinking straws for 1 minute. Record color of solution. Titrate color of solution back to original color with drops of 0.1 M NaOH solution. Record number of drops.