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Unformatted text preview: n why the concentration of N2O4 decreases. The reaction is endothermic. For endothermic reactions, increasing the temperature drives the reaction to the right. This increases the equilibrium concentration of NO2 and decreases the equilibrium concentration of N2O4. One point is earned for the correct explanation. (ii) The value of Keq at 25°C is 5.0 × 10− 3. Will the value of Keq at 100°C be greater than, less than, or equal to this value? Because the reaction is endothermic, at higher temperatures the reaction goes further to the right. This means that the value of Keq at 100°C will be greater than the value of Keq at 25°C. One point is earned for the correct choice. (No explanation required.) (d) Using the value of Keq at 25°C given in part (c)(ii), predict whether the value of ΔH° is expected to be greater than, less than, or equal to the value of TΔS° . Explain. Keq at 25°C is less than 1, hence ΔG° must be positive. And in order for ΔG° to be positive, ΔH° must be greater than TΔS°. One point is earned for the correct prediction. One point is earned for the explanation. © 2008 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com....
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This note was uploaded on 05/05/2011 for the course CHEM 504 taught by Professor John during the Fall '11 term at American College of Computer & Information Sciences.
- Fall '11