H2O Rocket Lab Write-up
Data: Complete the following data table:
Data Table 1.
Oxygen : Hydrogen Gas Mixtures and Rocket Flight Distance
Hydrogen:Oxygen
Ratio by Volume
Distance (m)
Trial 1
Distance (m)
Trial 2
Distance (m)
Trial 3
Average
Distance (m)
0:6
1:5
2:4
3:3
4:2
5:1
6:0
Data Table 2. Change in Water Mass with Optimal Gas Mixture on Rocket Flight Distance
(Design a table of your own for this portion of the lab)
Conclusion
1. Write a balanced chemical equation for the combustion reaction of hydrogen and oxygen gases to
give water.
2. How many moles of hydrogen react with how many moles of oxygen to give how many moles of
water?
3. When the reactants in a mixture are present in the exact mole ratio given by the balanced chemical
equation, all of the reactants should be used up when the reaction over. There will be no ‘leftover’
reactants. However, if one of the reactants is present in an amount greater than its mole ratio, then
that reactant cannot react completely, and some of it will be left over at the end of the reaction.
Use the mole ratio of hydrogen to oxygen to determine what happens when various
hydrogen/oxygen gas mixtures are allowed to burn. Complete the following table to indicate which
reactant (H2 or O2) is present in excess, and how much of it (how many “parts”) will be left over after
the combustion reaction is complete. Note: The second one has been completed as an example.
Part H2
Parts O2
Excess
substance?
How many parts
left over?
6
0
5
1
4
2
3
3
2
4
1
5
0
6
H2
3
4. Compare and contrast your optimum ratio determined by you experimentally to the stoichiometric
ratio of oxygen and hydrogen gas shown in the balanced equation in question #1. Explain any
discrepancy you observed between expected and actual results.
5. What is the stoichiometric reason for your ‘best’ reaction / distance for rocket?
6. Why do the hydrogen and oxygen gas mixture in the rocket not react as soon as they are collected?
Note: Consider the role of the igniter and the properties of gas molecules at room temperature.