Question

in the graph above, notice that the solubility of some compounds is increasing with increasing temperature while the solubility of hcl, nh₃ and so₂ decreases when the temperature increases. why does this happen? because hcl, nh₃ and so₂ are gases and the rest of the compounds are solids. because hcl, nh₃ and so₂ are exceptions to the rules. because hcl, nh₃ and so₂ are molecular compounds and the rest are ionic compounds. because hcl, nh₃ and so₂ are polar compounds and the rest are ionic compounds.

Explanation:

To solve this, we analyze the solubility behavior of gases vs. solids. Gases (like HCl, NH₃, SO₂) have solubility that decreases with increasing temperature (as higher temp reduces gas solubility in liquid, due to gas molecules escaping). Solid solutes (like salts) generally have increasing solubility with temp. The first option correctly identifies HCl, NH₃, SO₂ as gases and others as solids, explaining the solubility trend. The other options are incorrect: "exceptions" is not a valid scientific reason, molecular/ionic or polar/ionic distinctions don't explain the temp - solubility trend for gases vs. solids.

Answer:

A. Because HCl, NH₃ and SO₂ are gases and the rest of the compounds are solids.