HELP ASAP PLEASE!!

Question

25.Without doing any calculations, determine the sign of DS_sys for each chemical

       reaction.

(i) Mg(s) + Cl₂(g) → MgCl₂(s)

(ii) 2H₂S(g) + 3O₂(g)  → 2H₂O(g) + 2SO₂(g)

(iii) 2O₃(g)  → 3O₂(g)

(iv) HCl(g) + NH₃(g) → NH₄Cl(s)

Answer 1

Assuming DSsys refers to change in entropy of the system, the answers would be the following

1. (-)
2. (-)
3. (+)
4. (-)

The trick to do is to realize that gases have the highest entropy, followed by liquids, and then by solids. Looking to which direction of the equation produces the largest quantity of moles of gas will give the direction of entropic change.