February 2, 2011: Other Conversions, Volume and Heat (Angelo)

Volume and Heat:
- volume  at STP can be found using the conversion factor 22.4 L/mol (litres/mol)
- heat can be included as a separate term in chemical reactions (this is called ENTHALPHY)
- reactions that release heat are exothermic
- reactions that absorb heat are endothermic
- both can be used in stoichiometry

EXAMPLES:


1. If 5.0 grams of Potassium chlorate decompose according to the reaction below, what volume of Oxygen gas (at STP) is produced?

Create your balanced equation: 2KClO3 -----> 2KCl + 3O2
Create your equation: 5.0 grams * (1 mol / 122.5 g.) * (3 mols / 2 mols) * (22.4 L. / 1 mol) = ?
Calculate: 5.0 grams * (1 mol / 122.5 g.) * (3 mols / 2 mols) * (22.4 L. / 1 mol) = 1.4 L.