PPT Slide
- The energy released or absorbed during a reaction is due mostly to difference in PE between the reactant bonds and the product bonds.
- In a chemical reaction, reactant bonds are broken and product bonds are formed. 2H2(g) + O2(g) => 2H2O(g)
- When 2 g H 2 (1 mol) and 16 g O 2 (0.5 mol) react at 25ƒC, 18 g water vapor (1 mol) forms and 242 kJ of heat is released.
- Total reactant bond energy (1 mol H2 bonds and 0.5 mol O2 bonds) is greater than the total product bond energy(1 mol H2O bonds).
- The difference is released as heat (242 kJ)