Quiz: Heat, Q and  H rxn questions/calculations Take out your table with  H formation values on it.

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Quiz: Heat, Q and  H rxn questions/calculations Take out your table with  H formation values on it.

Be Able to: Determine and explain endothermic/exothermic processes Calculate using Q and  H values Describe the three types of heat transfer: – Radiation – Convection – Conduction

How much heat is released when 2.00 moles of water freeze? kJ of heat

How much energy is needed or released to combust 64.0 g of methane if it has a heat of combustion value of -891 kJ/mol? Use dimensional analysis kJ

842 kJ of energy is released by the combustion of an unknown amount of glucose (C 6 H 12 O 6 ); How much glucose (in grams) was combusted?  H comb = kJ/mol Use dimensional analysis 54.0 g

What is the specific heat of a substance whose temperature changes from 35.0 o C to 78.5 o C when it absorbs 625 J of heat if its mass is 45.6g? Use Q = mc  T J/g o C

If 335g of water is initially at 65.5 degrees Celsius loses 9750 J of heat, what is the final temperature of the water? Use Q = mc  T Solve for Tfinal 58.5 Degrees Celsius

15.0 g of water at 0.00 degrees Celsius is added to 45.0g of water at 40.0 degrees Celsius. What is the final temperature of the water mixture? Use Q = mc  T (2X) Qwater1 = -Qwater o C

Calculate the  H rxn of the reaction of ammonia (NH 3 ) decomposing to form nitrogen and hydrogen gases. Is it an exothermic or endothermic rxn? 2NH 3(g)  3H 2 (g)+ N 2 (g)  H rxn = Products – Reactants (*Get values from chart) kJ Endothermic

Calculate the  H rxn for the reaction of sulfur dioxide gas with oxygen gas to form sulfur trioxide gas. Is it an exothermic or endothermic process? 2SO 2 (g) + O 2  2SO 3 (g)  H rxn = Products – Reactants (*Get values from chart) -316 kJ Exothermic