Chapter 5 – Rocket
Challenge.
Your Challenge is to build a bottle rocket that will go as high as possible.
You have 3 choices as to how to launch your rocket. You will be graded on
style, the height obtained and a detailed explanation of the chemistry
involved. All groups must use a 2 L soda bottle, and all rockets will be
launched using the same launchers.
Choices:
1. Air Pressure rocket. The rocket is pumped up with air and
released. You need to include calculations of pressure and explain how
your rocket is propelled upwards.
2. Water pressure rocket. The rocket is filled about ½ way with water
and the pressure is increased. You need to investigate the best
proportions of water to air and give a detailed explanation of how the
rocket is propelled upwards.
3. Hydrogen- Oxygen rocket. The rocket is filled with a mixture of
hydrogen and oxygen and ignited with a spark. You need to include the
chemistry of the reaction (including how H2 and O2 are formed, and
the ratios used) and how this is used to propel the rocket upwards.
Air Pressure Rocket.
1.
2.
3.
4.
Calculate the volume contained in 1 pump of the bicycle pump.
Measure the exact volume of the bottle.
Count the # of pumps required to launch the rocket.
Calculate the pressure of the gas inside the bottle using the volume of air
pumped into it and Boyles Law (P1V1=P2V2)
5. Using the ideal gas law, how many moles of air are in your bottle?
6. Assuming air is 80% nitrogen and 20% oxygen, how many moles of each
are in your bottle?
7. Measure the mass of the bottle before being pumped full of air.
8. Using the molar mass of nitrogen and oxygen, calculate the mass of the
bottle after it is pumped full of air.
9. Calculate the pressure of your rocket at O ˚C and 50 ˚C.
10. What volume would the gas take up at these temperatures?
11.Explain what happens, in terms of pressure and volumes of the air when
the launch trigger is pulled.
12.Would you expect your rocket to go higher or lower at 50 ˚C than at O˚C?
Explain your reasoning.
Data
Temp: ___________________ Pressure ______________________
Volume of rocket _______________________________________
Volume of 1 pump (air)___________________________________
Mass of empty rocket____________________________________
# of pumps needed to launch_______________________________
Height rocket reached ___________________________________
Water Pressure Rocket.
1. Measure the volume contained in 1 pump of the bicycle pump.
2. Research on the internet, the effect of different volumes of water in your
rocket. Choose an amount of water you want to put in your bottle.
3. If this much water is in the bottle, how much air is in the bottle?
4. Count the # of pumps required to launch the rocket.
5. Calculate the pressure of the gas inside the bottle using the volume of air
pumped into it and Boyles Law (P1V1=P2V2)
6. Using the ideal gas law, how many moles of air are in your bottle when it is
launched?
7. Assuming air is 80% nitrogen and 20% oxygen, how many moles of each are
in your bottle?
8. Using the density of water (1g/ml), and the mass of the empty bottle
calculate the total mass of the bottle (including water) before it is pumped
full of air.
9. Using the molar mass of nitrogen and oxygen, calculate the mass of the
bottle after it is pumped full of air.
10. Explain, in terms of pressure and volume of air and water, what happens
when the rocket is launched.
11. How does the addition of water to the rocket affect how far it goes?
Compare your results to those of the air rockets and other water rockets.
12. How would the launch be effected by temperature. Would you expect your
rocket to go higher or lower on a hot day (40 ˚C) than a cold day ( 0 ˚C)
Temp: ___________________ Pressure _____________________
Volume of rocket _______________________________________
Volume of 1 pump (air)___________________________________
Mass of empty rocket____________________________________
Volume of water used____________________________________
# of pumps needed to launch_______________________________
Height rocket reached ____________________________________
Hydrogen- Oxygen Rocket
1.
2.
3.
4.
Write a balanced equation for how you produced the hydrogen gas.
Write a balanced equation for you produced the oxygen gas.
Write a balanced equation for the reaction inside your bottle.
What ratio of hydrogen to oxygen did you use to fill your bottle? Why
did you choose this ratio?
5. Using the volume of hydrogen you put in the bottle, how many moles of
water were produced?
6. Using the volume of oxygen you put in the bottle, how many grams of
water were produced?
7. What state was the water you produced (s, l, g?) Where did it go when
your rocket was launched?
8. Explain, in terms of energy of the reaction, why your rocket was
propelled upwards during the reaction?
9. Is this reaction exothermic or endothermic? Explain how you know.
10. Using the volume of hydrogen you produced and atmospheric pressure
and room temperature, calculate the volume the hydrogen would be at
1 atm and 273K.
11.What amount (in L) of hydrogen would be required to produce 2L of
water vapor.
12.How many moles of oxygen would be required to fill a 2L bottle to 3 atm
of pressure at 35 ˚C?
Data
Temperature ___________________________ Pressure ____________
Volume of bottle ____________________________________________
Volume of hydrogen used ____________________________________
Volume of Oxygen used ______________________________________
Height reached by rocket ______________________________________