3.9.5: Lecture Demonstration- Carbide Cannon
- Page ID
- 50737
Enthalpy of reactions:
Assuming you want about a 1 kJ explosion, how much CaC2 would you add to a carbide cannon?
(1) 2 C2H2 + 5 O2 → 4 CO2 + 5 H2O ΔH ?
given
(2) C + O2 → CO2 ΔHf = -393.5 kJ/mol
(3) H2 + 1/2 O2 → H2O (g) Δ Hf = -241.82 kJ/mol
(4) 2 C + H2 → C2H2(g) ΔHf = +226.7
Calculated enthalpy change for combustion of 2 mol of acetylene, ΔH = -2511 kJ
This is 48.2 kJ/g
for 1 kJ, we need 1 kJ/48.2 kJ/g = 0.02 g of acetylene
CaC2 + 2 H2O → HCCH + Ca(OH)2
this requires 0.0008 mol of CaC2, which is 0.05 g.
Do it with a Bangsite Cannon!
Contributors
Ed Vitz (Kutztown University), John W. Moore (UW-Madison), Justin Shorb (Hope College), Xavier Prat-Resina (University of Minnesota Rochester), Tim Wendorff, and Adam Hahn.