1. GRAIN ELEVATOR MODEL DIAGRAM Paint can Candle Funnel Lycopodium Tubing Air source

2. CHEMISTRY  Reaction: ( C 6 H 10 O 5 ) n (s) + O 2 (g)  CO 2 (g) + H 2 O (g)  This is a combustion reaction.  The candle provides the “activation energy”—the energy required to get a reaction going/started.  Increased surface area creates a chain reaction  EXPLOSION (food dust).

3. ENERGY  E a H reactants products REACTION PROGRESS  Potential Energy Diagram

4. Explosion of DeBruce Grain Elevator Wichita, Kansas 8 June 1998

5. Source: US Department of Laborwww.osha.gov/as/opa/foia/debruce-cover1.jpg

6. 225 kJ – 75 kJ = 150 kJ (kJ)