MasteringChemistry: Chapter 9 Homework - Google Chrome https://session.mastering
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MasteringChemistry: Chapter 9 Homework - Google Chrome https://session.masteringchemistry.com/myct/itemView?assignmentProblem ID=56488538&offsets; next CHM260 Signed in as basem fodah Help Close Chapter 9 Homework Exercise 9.83 Resources « previous | 12 of 14 | next» Exercise 9.83 Part A Hydrogen, a potential future fuel, can be produced from carbon (from coal) and steam by the following reaction C(s, graphite) + 2 H2O(g) 2 H2 (g) + CO2 (g) Use average bond energies to calculate AHrxn for this reaction Note that the average bond energy for the breaking of a bond in CO2 is 799 kJ/mol. kJ Submit My Answers Give Up Provide Feedback Continue 7:32 PM 11/23/2015Explanation / Answer
Answer – We are given the reaction
C(s,graphite) + 2H2O(g) -----> 2 H2(g) + CO2(g)
We know the bond energy is the sum of the bond energy of reactant subtract sum of the bond energy of product
Hrxn= sum of bond breaking – sun of the bond formation
= [ 4 *B.E O-H ] – [2*B.E H-H + 2 B.E C=O ]
= (4 * 467) – ( 2*432 +2*799)
= -594 kJ