Final answer:
The solids tested are listed from least polar (naphthalene) to most polar (NaCl), based on their molecular structures and expected interactions with various solvents. Naphthalene is least polar due to only having London dispersion forces, benzoic acid is moderately polar, urea has higher polarity due to potential hydrogen bonding capability, and NaCl is the most polar due to its ionic nature.
Step-by-step explanation:
To list the solids tested in order of increasing polarity, we must consider the molecular structure and the interactions each solid can have with the solvents used. Here are the solids in order from least polar to most polar:
- C₁₀H₈ (Naphthalene): It is a nonpolar compound with only London dispersion forces, resulting in weak interactions with polar solvents and therefore low solubility in water.
- C₆H₅COOH (Benzoic Acid): It has a polar carboxylic acid group and a nonpolar aromatic ring, making its polarity and solubility in water moderate.
- NH₂CONH₂ (Urea): While not specified in the given text, urea is known to be highly soluble in water due to its ability to form hydrogen bonds with water molecules, suggesting higher polarity than benzoic acid but potentially less than salts.
- NaCl: A salt generally considered highly polar due to its ionic nature and strong interactions with water, resulting in high solubility.
This order is based on the general principle that 'like dissolves like': nonpolar compounds like naphthalene dissolve better in nonpolar solvents (such as hexane), whereas polar and ionic compounds like NaCl dissolve better in polar solvents (like water).