Vehicle air bags protect passengers by using a chemical reaction that generates gas rapidly. Such a reaction
Question:
Vehicle air bags protect passengers by using a chemical reaction that generates gas rapidly. Such a reaction must be both spontaneous and explosively fast. A common reaction is the decomposition of sodium azide, NaN3, to nitrogen gas and sodium metal.
(a) Write a balanced chemical equation for this reaction using the smallest whole-number coefficients.
(b) Predict the sign of the entropy of reaction without doing a calculation. Explain your reasoning.
(c) Determine the oxidation number of nitrogen in the azide ion and in nitrogen gas. Is nitrogen oxidized or reduced in the reaction?
(d) Use the data in Appendix 2A and the fact that, for sodium azide, Sm° 5 96.9 J · K–1 · mol–1, to calculate ΔS° at 298 K for the decomposition of sodium azide.
(e) Use your result from part(d) and the fact that, for sodium azide, ΔHf° = 121.7 kJ · mol–1, to calculate ΔH° and ΔG° at 298 K for the decomposition of sodium azide.
(f) Is the reaction spontaneous at 298 K and a constant pressure of 1 bar?
(g) Can the reaction become nonspontaneous (at a constant pressure of 1 bar) if the temperature is changed? If so, must the temperature be raised or lowered?
Step by Step Answer:
Chemical Principles The Quest For Insight
ISBN: 9781464183959
7th Edition
Authors: Peter Atkins, Loretta Jones, Leroy Laverman