* Calculate the Enthalpy Change ( H) for the Reaction Below Using

* A student combines sodium hydroxide with hydrochloric acid solutions so their combined mass is 152.40 grams. Initially each was at 22.500C. After the reaction occurred the temperature of the mixture was 28.000C. a. How much heat energy was transferred in this reaction? b. Was the reaction endothermic or exothermic? How could you tell?

* Calculate the enthalpy change (∆H) for the reaction below using Appendix 1, A3 in your textbook. 4 NH3(g) + 5 O2(g)  4 NO(g) + 6 H2O(g) * Complete combustion of acetone, C3H6O, results in the liberation of 1760 kJ of heat. C3H6O(l) + 4 O2(g)  3 CO2(g) + 3 H2O(l)

Using the information above and in Appendix 1 A3, calculate the enthalpy of formation of acetone.

* A reaction occurs when hydrogen gas is added to nitrogen gas at 6000C to produce liquid hydrazine. a) Calculate the change in entropy for the universe for the production of liquid hydrazine at the above temperature.

b) Is the reaction spontaneous at this temperature? How can you tell? * If acetylene gas (C2H2) is burned in oxygen gas at a temperature of 35oC, will the reaction be spontaneous?

* One of the ingredients for making cement is calcium oxide (lime). Lime is usually produced by heating solid calcium carbonate found in limestone. The calcium carbonate decomposes into solid calcium oxide and carbon dioxide gas. At what temperature will this reaction become spontaneous? *Thermite reaction (do the reaction and then students do this problem)

a. Write a balanced equation for the thermite reaction that was done outside when solid aluminum was reacted with solid ferric oxide.

b. Calculate the temperature at which the reaction is spontaneous.

c. Initially the chemicals were mixed together and the following data was collected mass of the flask = 139.71 g mass of flask + Al = 147.41 g mass of flask + Al + Fe2O3 = 172.13 g What was the change of enthalpy for the reaction based upon the amount of chemical used?

d. If the reaction in part “c” was performed while being surrounded by 40.0 kg of water at an initial temperature of 250C, what would be the water’s final temperature?