Question

Without doing any calculations, determine the sign of ?Ssys for each chemical reaction.
a. Mg(s) + Cl2(g) ? MgCl2(s)
b. 2 H2S(g) + 3 O2(g) ? 2 H2O(g) + 2 SO2(g)
c. 2 O3(g) ? 3 O2(g)
d. HCl(g) + NH3(g) ? NH4Cl(s)