Answer
B
Work Step by Step
N2g 2-O2g 2-NO2g
$\Delta S_r^0=2S^0(NO_2(g))-2S^0(O_2(g))-S^0(N_2(g))$
$\Delta S_r^0=2\times240.04-2\times205.07-191.56$
$\Delta S_r^0=-121.62\ J/K.mol-rxn$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.