three Alka Seltzers (per student or group)
three clear cups
Zip Lock bags
stop watch/clock
measuring cup
wooden block or mug
Concept: Particle size does matter. The smaller the piece of Alka Seltzer; the faster the reaction time to dissolving. It takes longer for the larger piece to dissolve than the smaller or crushed piece.
Procedure: Fill a measuring cup with 1 cup of water. Place a whole Alka Seltzer in an empty clear plastic cup. Pour 1 cup of water into the clear plastic cup with the Alka Seltzer. Use a stop watch or clock to time how long it takes the Alka Seltzer to dissolve. Ask the students to look and listen. Next, break alka Seltzer into equal size parts (4 to 8 pieces) Pour 1 cup of water into 2nd clear plastic cup with pieces of Alka Seltzer and time seconds till particle is dissolved. Last, place whole Alka Selzer in bag and use block or bottom of mug to crush into a powder. Place powder in 3rd plastic cup and pour 1 measured cup of water and time seconds till dissolved.
Extension: Vary temperature of water (hot tap, warm tap, and cold/ice) and used thermometer to take temperature of water and repeat experiment. Stir the Alka Selzer and water to test if reaction time is faster or slower.
Application to Real World: Alka Seltzer is a antacid and pain reliever. A huge marketing strategy used for this medicine is its ability to provide fast relief to acid indigestion, upset stomach, heartburn with head ache/body aches. The Alka Seltzer tablet has a quicker reaction time in dissolving in comparison to many other medicines.
