Question

entropy increases when the degrees of freedom increases. usually, if the number of molecules increases then the entropy increases. predict the δs for these chemical processes: rust forms on a pipe: fe + 3 o₂ → fe₃o₄ a δs is (+) b δs is (-) c δs = 0

Explanation:

Step1: Analyze reactants and products

Reactants: Fe (solid) and \(3O_2\) (gas). Products: \(Fe_3O_4\) (solid).

Step2: Determine change in disorder

Gaseous molecules ( \(O_2\)) are converted to a solid product. Gases have higher entropy than solids. The number of gaseous molecules decreases (from 3 moles of \(O_2\) to 0 moles of gas in product), so disorder (entropy) decreases.

Step3: Relate to \(\Delta S\)

A decrease in entropy means \(\Delta S\) is negative.

Answer:

B. \(\Delta S\) is (-)