Answer:
Explanation:
A gives off a visible gaseous product when the two are mixed.
The others all talk about physical properties like phase changes and densities.
<span>This was one of the old regents. I didn't get this at first glance too so I searched for it and I got this site. lol. I know what to do now. To get a higher boiling point, you have to find which solution has the most moles. Since SO4, PO4, and NO3 are all polyatomic ions, they only count as one mole. </span>