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U 2/13/2017 11:55 PM A 82.2/100 2/13/2017 04:12 AM Gradebook Print Calculator Periodic Table Question 13 of 13 Map data A EA Sapling Learning Calculate the standard change in Gibbs free energy for the following reaction at 25 eC. AG"r values can be found here 2C,H 70, g Number AG 2.88 kJ AO Previous Give Up & View solution & Try Again O Next Exit Explanation The change in the standard Gibbs free energy of a reaction is given by AG 2nAG, products 2mAG, reactants where AG" is the standard free energy of formation, and n and mare coefficients in the chemical reaction AG f values can be found here For this reaction, what are the reactants, and what are their coefficients? What are the products and their coefficients? O Assignment Information Available From 2/7/2017 08:00 AM 2/13/2017 55 PM Due Date: Points Possible: 100 Grade Category: Graded Description: Policies: Homework You can check your answers. You can view solutions when you complete o up on any question. You can keep trying to answer each question you get it right or give up. You lose 5% of the points available to each ar in your question for each incorrect attempt a answer. Oe Textbook o Help With This Topic O Web Help & Videos O Technical Support and Bug Reports

Explanation / Answer

the standard change in gibbs free energy

2C2H6(g) +7O2----à4CO2 (g) +6 H2O

G = Gf (products) – Gf (reactants) at standard temperature (298K).

bond enthalpies

(C-H = 413 kJmol-1,

O=O =495 kJmol-1,

C-C =348 kJmol-1,

C=O =799 kJmol-1,

O-H =463 kJmol-1

ethane, C2H6, and oxygen, O2

. Each ethane molecule has 1 C-Cbonds and 6 C-H bonds

with 2 moles of ethane,

break 2 C-C bonds and 12 C-H bonds.

O=O. Since you have 7 moles present, you'll need to break 7 such bonds.

Bonds formed

CO2, and H2O.

2 C=O bonds, and since you're forming 4 moles,--------- form 8 such bonds.

2 H-O bonds per molecule, so the 6 moles produced ----------- 12 such bonds.

Calculate the standard change in gibbs free energy