Worksheet 17C Heat Terms Are Stoichiometric

Worksheet 17C Heat Terms Are Stoichiometric Name_____________________ 1) For the following reaction: CaCO3 (s) r CaO(s) + CO2(g) Given: r H = +178 kJ/mol a) How many kilojoules of heat energy is involved in the above reaction if 3 moles of CaCO3 were to decompose? b) Is this reaction endothermic or exothermic? The sign of r H = ______ c) Which side of the equation would the heat term be on: right or left ?(circle one). 2) For the following reaction: H2 (g) + Cl2(g) ? 2HCl (g) + 185kJ a) How many kilojoules of heat energy is released if 2.5 moles of H2 reacts with an excess of chlorine gas? b) Is this reaction endothermic or exothermic? r H = positive or negative (circle one)? c) How many moles of HCl would be produced if 2.5 moles of H2 reacts with an excess of chlorine gas? 3) For the following reaction: 2KClO3(s) + 156 kJ r 2KCl (s) + 3O2 (g) How many kJ of heat energy is absorbed if 16 moles of KClO3 were to decompose? b) Is this reaction endothermic or exothermic? The sign of r H = ______ How many moles of KCl and O2 are produced if 16 moles of KClO3 were to decompose? 4) For the following reaction: 2NH3 (g) + 92 kJ ? N2(g) + 3H2(g) a) How many kilojoules of heat energy is absorbed in the above reaction if 0.50 moles of NH3 reacts? b) r H has what sign?______Is this reaction endothermic or exothermic? (Circle one) c) How many moles of nitrogen gas are produced if 0.50 moles of NH3 reacts? 5) For the following reaction: NH4NO3(s) r N2O (g) + 2H2O (g) Given: r H = -99 kJ/mol a) How many kilojoules of heat energy is released in the above reaction if 4.5 moles of NH4NO3 decomposed? b) r H has what sign?______Is this reaction endothermic or exothermic? (Circle one) c) How many moles of water would be formed if 4.5 moles of NH4NO3 are decomposed? Answers: 1) 534 J or 5 X 102kJ (1 sf ) 2) 463kJ or 4.6 X102 kJ (2sf), 5.0moles HCl 3) 1248kJ or 1.2 X 102 kJ (2 sf), 16 mol KCl and 24 moles O2 4) 23kJ, 0.25 mole N2 5) 446kJ or 4.5 X 10 2kJ (2 sf), 9.0 mol H2O