E. Population of a city is a state function. If we start with a certain population, then withdraw and add people to the cities population, we can come back to the original population. D 7
25 Chem 161-2007 Exam II Hill, Petrucci et al., 4 th edition Chapter 6 - ThermochemistryHeat and work In which of the following processes is w = 0?X.Combustion takes place in a bomb calorimeter (fixed volume)Y.1.0 mol H2O() changes to 1.0 molH2O(g) under 1 atm pressureZ.NH3(g) + HCl(g) NH4Cl(s) A. X onlyB. Y onlyC. Z onlyD. X and Z onlyE. X,Y, and ZWork = -P∆VX. Since the volume doesn’t change in a bomb calorimeter, ∆V = 0, so work is 0.Y. When 1.0 mol of H2O(l) changes to 1.0 mol of H2O(g), there is an expansion of volume, meaning that work is being done on the surroundings. Hence, work ≠ 0.Z. When two gases become a solid, there is a decrease in volume, meaning that work is being done on the system, so work ≠ 0. 8
15 Chem 161-2006 Final Exam Chapter 6 – Thermochemistry Heat and Work What volume change will a system undergo if it absorbs 4.55kJ of heat and ΔU is 3.26kJ and the external pressure is 0.833atm? D CHEM 161-2006 EXAM II HILL & PETRUCCI CHAPTER 6 THERMODYNAMICS HEAT AND WORK 10. A gas absorbs 125 J of heat and expands from 2.00 L to 5.00 L under a constant pressure of 1.00 atm. CalculatU for this process.(a) 122 J(b) 429 J(c) -179 J(d) -122 J(e) 347 J 9
ENTHALPY Chem 161-2011 Exam I Burdge and Overby, Chapter 1 – Chemistry: Science of Change Enthalpy Correlates to Hill & Petrucci Chapter 6 2. Which of the following are intensive properties? 1. volume 2. boiling point 3. mass 4. density A. 1, 2, 3, and 4 B. 1 and 3 C. 2 and 4 D. 1, 3 and 4 E. 2 and 3 Extensive property: Depends on the quantity. e.g., volume is an extensive property. Intensive property: Doesn’t depend on the quantity; e.g., temperature, density. Go from 100 mL of a substance to 200 mL of that substance, what changes? 1. Volume. The volume increases. Therefore, volume is an extensive property. 2. Boiling point. The boiling point doesn’t change. Therefore, boiling point is an intensive property. 3. Mass. The mass increases. Therefore, mass is an extensive property. 4. Density. The density doesn’t change. Therefore, density is an intensive property. 10
12 Chem 161-2010 Exam III Chapter 6 - Thermochemistry Enthalpy
You've reached the end of your free preview.
Want to read all 74 pages?