Which of the following reactions would have a decrease in entropy?
A. 2H20(g) → 2H2(g) + O2(9)
B. 2503(9) ► 2502(g) + O2(g)
C. 2NH3(9) ► N2(g) + 3H2(9)
D. 2NO2(g) → N204(9)