Chapter 4 &5Supplemental InstructionIowa State UniversityLeader: KatieCourse: Chem 177Instructor: BurnettDate: February 28th, 20101. a) What is meant by the term system in thermodynamics?b) What is a closed system?2. a) State the first law of thermodynamics.b) What is meant by the internal energy of a system?c) By what means can the internal energy of a closed system increase?3. a) Write an equation that expresses the first law of thermodynamics in terms of heat and work.b) Under what conditions will the quantities q and w be negative numbers?4. Calculate ΔE, and determine whether the process is endothermic or exothermic for the following cases:a) A system absorbs 105 kJ of heat from its surroundings while doing 29 kJ of work on the surroundings.b) The system releases 57.5 kJ of heat while doing 22.5 kJ of work on the surroundings.5. Suppose that the gas-phase reaction 2NO(g) + O2(g)→2 N O2(g) were carried out in a constant-volume container at constant temperature. Would the measured heat change represent ΔH or ΔE? If there is a difference, which quantity is larger for this reaction?6. Consider the following reaction: 2 Mg(s)+O2(g)→2 MgO(s) ΔH = -1204kJa) Is this reaction exothermic of endothermic? b) Calculate the amount of heat transferred when 2.4g of Mg(s) reacts at constant pressure. c) How many grams of MgO are produced during an enthalpy change of -96.0 kJ? Supplemental Instruction1060 Hixson-Lied Student Success Center v 294-6624 v www.si.iastate.edud) How many kilojoules of heat are absorbed when 7.50g of MgO(s) is decomposed intoMg(s) and O2(g) at constant pressure?7. The specific heat of ethylene glycol is 2.42 J/g-K. How many J of heat are needed to raise the temperature of 62.0g of ethylene glycol from 13.1ºC to
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