120 likes | 436 Views
BTB - bromthymol blue solution (indicator). Used to detect the presence of carbon dioxide. Turns YELLOW if CO 2 is present. exercise. Same person exhaling Constant breathing Time of exhalation. Rate of change in BTB. A: Measure CO2 exhaled at rest
E N D
BTB- bromthymol blue solution (indicator) Used to detect the presence of carbon dioxide Turns YELLOWifCO2is present
exercise • Same person exhaling • Constant breathing • Time of exhalation Rate of change in BTB A: Measure CO2 exhaled at rest B: Measure CO2 exhaled after exercise Measure time for BTB to change from blue to yellow Measure no. of drops needed to change BTB back • Practice breathing out to maintain constant exhalation • Control accuracy of size of drops
EXPERIMENT Will exercise affect the rate of change in BTB solution? Independent variable (tested/changed) Dependentvariable (measured/result) Control Student at Rest Experimental/Test Group) Student Exercising • FAIR TEST (AVOID errors) • same person tested • constant breathing • same breathing time COLLECT DATA
If exercise is done then, the rate of change of BTB will be (faster/slower) because (more/less) carbon dioxide is produced during exercise. When a person exercises, (explain your understanding of breathing and respiration).
Add drops of Ammonia (base) until solution is neutralized (changes back to blue) PART A. At Rest (three trials) Blow air for 1 min (CO2) Record the time the solution changes color. Changes to YELLOW if CO2 is detected BTB solution CO2 + Water forms an acid
Add drops of Ammonia (base) until solution is neutralized (changes back to blue) PART B. After exercise (three trials) Exercise for 1 min Blow air for 1 min (CO2) Record the time the solution changes color. Changes to YELLOW if CO2 is detected BTB solution
Ammonia Acid Base Neutral X no of drops of ammonia needed to neutralize Acid in BTB solution