-Volume at STP can be found using this conversion factor 22.4 L/mol
-Heat can be included as a separate terms in chemical reactions (This is called Enthalpy)
-Rxns that release heat are exothermic
-Rxns that absorb heat are endothermic
-Both can be used in stoichiometry
ex: If 5.0 g of Potassium chlorate decompose according to the reaction below, what volume of Oxygen gas (at STP) is produced?
2KClO3 > 2KCL + 3O2
5.0 g x 1mol/122.6 g x 3/2 x 22.4 L/ 1 mol = 1.4 L of Oxygen
ex2: When Zinc reacts with hydrochloric acid exactly 1.00 L of hydrogen gas is produced (at STP). What mass of Zinc was reacted?
Zn +2HCl > ZnCl2 + H2
1.00 L x 1mol/22.4 x 1/1 x 65.4 g / 1 mol = 2.92 g of Zinc
- Paul Dinh
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