chapter 1 - title demo week ii. “whoosh bottle” bottle, alcohol, match 2 effects –detonation...
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Chapter 1 - Title
Demo Week II
“Whoosh Bottle”
• Bottle, alcohol, match• 2 effects
– Detonation“whoosh’ thrust (methanol)
– BurningCone/ring of fire (propanol)
• Depends on v.p., – All burn if diluted
• Fortman et al, 1999; Campbel et al., 2001
methanol > ethanol > 2-propanol > propanol
Safety
• No glass– Shatters
• Use air, NOT oxygen• Do not heat• Pressurized
– Avoid spray• Excess liquid melts the bottle
– Extinguish with cap• Goggles and safety shield
Procedure
• Add wheels• Jug MUST be dry• Add 0.75 mL methanol• Cap and slosh• Wait 20 mins
Rockets (Making Water)
• Fuel
HCl(aq) + Zn(s) ZnCl2(aq) + H2(g)
• Ignition
2H2(g) + O2(g) 2H2O(l)
Calculation
• Atmosphere provides 1 O2 molecule out of 5 we let in the bottle, Determine what ratio of H2 to air in a 2L bottle will provide a 2:1 ratio of H2:O2.
• Ratio O2 : N2 in air__ : __
• Ratio of Hydrogen : Oxygen in our rocket required for complete combustion
__ : __
• Ratio of Hydrogen : Air in our rocket required for complete combustion __ : __ (a : b)
__/__ : __/__ (divide by the total a+b)__% : __%
• ff
Solution
• 2H2 + O2 2H2O2 : 1 2
• Need 2 hydrogen molecules for every oxygen molecule• From air: 1 O2 for every 5 molecules of air we let in• Ratio of Hydrogen : Oxygen in our rocket required for complete
combustion
2 : 1• Ratio of Hydrogen : Air in our rocket
2 : 5 2/7 : 5/730% : 70%
• [1] ~ 570 mL of H2 and 1430 mL of air.
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