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# e3pf09key - 0 Graphite is thermodynamically less stable...

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0. Graphite is thermodynamically less stable that diamond under standard conditions. 1. True 2. False Graphite is thermodynamically more stable that diamond under standard conditions. 1. Which statement would be the best interpretation of the First Law of Thermodynamics? 1. The total amount of energy in the universe is increasing. 2. The total amount of entropy in the universe is increasing. 3. The total amount of energy in the universe is constant. 4. The total amount of matter in the universe is constant. The first law is the law of conservation of energy and mass (not matter). The second law deals with entropy. 2. Enthalpy (H) is best defined by which of the following statements? 1. the capacity of a system to influence the entropy of its surroundings 2. pressure-volume work 3. a measure of a system's energetic degeneracy 4. none of these describe enthalpy We know that the change in enthalpy of a sytem (whether it increases or decreases in a given system for a given process) affects the entropy of its surroundings, thereby influencing the spontaneity of a reaction. 3.1. Water changing from a solid to a liquid is 1. an endothermic change. 2. an exothermic change. 3. Neither an exothermic or an endothermic change Heat is always required for melting any substance. Melting is an endothermic process. 3.2. Heat flow is considered positive when heat flows (into, out of) a system; work is considered positive when work is done (by, on) a system. 1. out of; by 2. into; on 3. out of; on 4. into; by Heat flow q is considered positive when heat flows into a system. Work w is considered positive when work is done on a system. 4. Definition: state functions An extensive state function's value is (dependent on/independent of) the amount of a given substance. An intensive state function's value is (dependent on/independent of) the amount of a given substance. 1. dependent on, dependent on 2. independent of, independent of 3. dependent on, independent of 4. independent of, dependent on Extensive properties depend on the extent of the system (whence the term extensive); intensive properties do not. 5. What is the enthalpy change for ΔH° f C(s,graphite)? 1. −1300 kJ/mol 2. 31 kJ/mol 3. 717 kJ/mol 4. 0 kJ/mol 5. −575 kJ/mol

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For an element in its standard state at 25 °C, 1 atm, ΔH° f = zero. 6. Consider the following specific heats: copper, 0.384 J/g·°C; lead, 0.159 J/g·°C; water,4.18J/g·°C; glass, 0.502 J/g·°C. If the sameamount of heat is added to identical masses of each of these substances, which substance attains the highest temperature? (Assume that they all have the same initial temperature.) 1. lead 2. water 3. glass 4. copper Lead has the lowest specific heat, and thus requires the least heat in order to have an increase in temperature. Its temperature will thus increase the most for a given amount of heat. 7.1. You set up a bomb calorimetry experiment using 1 liter of water as your heat sink and
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## This note was uploaded on 09/12/2010 for the course CH 302 taught by Professor Holcombe during the Spring '07 term at University of Texas.

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e3pf09key - 0 Graphite is thermodynamically less stable...

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