https:// session masteringchemistry.com 49649257 CHM116 SU2015 He Ch 19 HW Third
ID: 882424 • Letter: H
Question
https:// session masteringchemistry.com 49649257 CHM116 SU2015 He Ch 19 HW Third Law of Thermodynamics Resources s 8 of 17 next Correct Third Law of Thermodynamics The third law of thermodynamics deals with the entropy of a system and the chemical bonding in the molecules. Whenever there is a change in phase from a solid to a liquid o from a liquid to a gas, the vibrational and rotational motions of molecules increase; therefore, the entropy of the system increases as the phase changes. At absolute zero, the entropy of any perfect system becomes zero. Entropy, denoted by the symbol S, is the thermodynamic property describing the amount of molecular randomness or disorder in a system. It is a state thermodynamic function, meaning that its value does not depend on the path used to arrive at a specific set of conditions. Each system with a specified temperature, pressure, and composition has a unique entropy value. Part B Calculate the standard-state entropy for the following reaction: 1 Al2O3 (s) 3H2(g) 2 Al(s) 3 H2O The entropy change, AS, is the difference in entropy (If applicable, coefficients of one have been included for clarity.) between two states of a system, such as between the The standard entropy values are given in the table reactants and products of a reaction or between a flask before and after adding a mixture of gas Formula J/(K mol) H2O(l) 189 A12 51.0 Express your answer with the appropriate units Value Units AS Subm Hints My Answers Give Up Review Part incorrect, Try Again; no points deducted The compound unit you entered is not recognizedExplanation / Answer
Delta Srxn = Sum Delta S product- sum delta S reactant
= [2 * Delta S of Al + 3 * delta S H2O ] – [ 1 * Delta S Al2O3 + 3 * Delta S H2 (g)
Lets plug given values in above equation
Delta S rxn = [2 * 28.0 J / K mol + 3 * 189 J/ K mol ] - [ 1 * 51.0 J / K mol + 3 * 131 J /k mol
=179 J / K
Delta S of reaction = 179 J/K
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.