Question

Which of the following reactions has the largest positive value of ΔS per mole of O2?

Which of the following reactions has the largest positive value of ΔS per mole of O2?

A) 2C(s) + O2(g) → 2CO(g)
B) 2NO(g) + O2(g) → 2NO2(g)
C) 2Mg(s) + O2(g) → MgO(s)
D) 2H2(g) + O2(g) → 2H2O(g)
E) C(s) + O2(g) → CO2(g)

Im not sure if its A or E

Answer 1

I make it `A`....

Explanation:

Entropy is the statistical probability for disorder. And, therefore, a GASEOUS phase will have more intrinsic disorder, more randomness, than a condensed phase...

For `A.` we gots...the transition `"1 mol of gas"rarr"2 mol gas"`

For `E.` we gots...the transition `"1 mol of gas"rarr"1 mol gas"`

Since gaseous phases DOMINATE the entropy term, `A` wins...