Question

Which of the following changes has a decrease in entropy? (3 points)
Answer

N2O4 (g) 2NO2 (g)

C2H5OH (l) + 3O2 (g) 2CO2 (g) + 3H2O (g)

3O2 (g) + 2KCl (s) 2KClO3 (s)

H2O (l) H2O (g)

Answer 1

@whpalmer4

Answer 2

The answer is 3O2 (g) + 2KCl (s) 2KClO3 (s)

Answer 3

entropy is a measure of disorder: a system loses entropy when the products are in a more ordered state than the reactants. In general:

1) solids are more ordered than liquids, which are more ordered than gases

2) 2 moles of a gas are more disordered than 1 mole of a gas

3) systems at higher temperatures are more disordered than systems at lower temps

those 3 tendencies are just about enough to answer any change in entropy question