Question

identify which compound, \\(\text{nh}_3\\) or \\(\text{ccl}_4\\), has a greater surface tension and why.

\\(\text{nh}_3\\) because it has the stronger intermolecular forces.
\\(\text{ccl}_4\\) because it has the weaker intermolecular forces.
\\(\text{nh}_3\\) because it has the weaker intermolecular forces.
\\(\text{ccl}_4\\) because it has the stronger intermolecular forces.

Explanation:

Analyze intermolecular forces

Using the Intermolecular Forces knowledge point

• \(\text{NH}_3\) (ammonia) exhibits hydrogen bonding, which is a very strong type of intermolecular force.
• \(\text{CCl}_4\) (carbon tetrachloride) is a nonpolar symmetric molecule that only exhibits weaker London dispersion forces.

Relate forces to surface tension

Using the Surface Tension Factors knowledge point

• Surface tension is directly proportional to the strength of the intermolecular forces holding the liquid molecules together.
• Stronger intermolecular forces lead to a greater surface tension.
• Therefore, \(\text{NH}_3\) has a greater surface tension because it has stronger intermolecular forces.

Answer:

• (A) \(\text{NH}_3\) because it has the stronger intermolecular forces. (Correct answer)
• (B) \(\text{CCl}_4\) because it has the weaker intermolecular forces.
• (C) \(\text{NH}_3\) because it has the weaker intermolecular forces.
• (D) \(\text{CCl}_4\) because it has the stronger intermolecular forces.