Pop Rockets PURPOSE: To predict and measure the effects of the amount of oxygen on the combustion of hydrogen gas. BACKGROUND: Hydrogen gas is highly flammable, and combusts with oxygen to make water. 2 H 2 + O 2  2 H 2 O

Pop Rockets METHOD: Teams will fill pipette bulbs with different ratios of hydrogen and oxygen gas produced by a fuel cell. You will then launch the bulbs using a piezoelectric igniter, measure the distance traveled, and judge the loudness of the pop. All teams will start with a half-and-half mix (3 parts O 2 & 3 parts H 2 ), and then do two other combinations as assigned.

Pop Rockets STEP 1: Water Go to the water filling station and fill your pipette bulb with water using the syringe and fill tube. STEP 2: Oxygen Go to the “gas station” and fill your pipette with your assigned amount of oxygen (in sixths of a bulb).

Pop Rockets STEP 3: Hydrogen Fill the pipette bulb the rest of the way with hydrogen, and “cap” the bulb with your finger. Pipette Bulb Fill Tube Insert the fill tube into the bulb and allow the gas to displace the water — about 1 drop per second.

Pop Rockets STEP 4: Launch When teams are ready, the bulbs will be launched using a piezoelectric igniter. All teams will judge the relative loudness on a scale of 0 – 10, with the loudness of the half & half bulb (which must be launched first) being defined as “5”. Your team will also measure the distance of flight for your bulb (by counting tiles). Teams will enter their results in the table that follows.

Pop Rockets RESULTS: O2O2 H2H2 Pop (0-10)Distance (tiles)

Pop Rockets RESULTS: Averages from 2012 & 2013 O2O2 H2H2 Pop (0-10)Distance (tiles)

Pop Rockets

QUESTIONS: See handout …

Pop Rockets