Question

water can form large dewdrops in nature. how would dewdrops made of saltwater instead of pure water be different?
a. saltwater can form the same large droplets as plain water because it has equal surface tension.
b. if saltwater formed dewdrops, they would be smaller because saltwaters surface tension is lower than that of pure water.
c. because of salts crystalline structure, saltwater would form lines, not droplets.
d. all liquids and solutions will form the same large droplets that water does.

Explanation:

Surface tension is the property of a liquid's surface that allows it to resist an external force. Pure water has a relatively high surface tension, which enables it to form large dewdrops. Saltwater, on the other hand, has dissolved salts. The presence of these salts disrupts the hydrogen - bonding network in water. Hydrogen bonds are responsible for the high surface tension in pure water. When the hydrogen - bonding network is disrupted (by the addition of salts in saltwater), the surface tension of the liquid decreases. A lower surface tension means that the cohesive forces between the liquid molecules are weaker. As a result, when saltwater forms dewdrops, the weaker cohesive forces (due to lower surface tension) cannot support as large a drop as pure water can. So, saltwater dewdrops would be smaller.

Now let's analyze each option:

• Option A: Saltwater does not have the same surface tension as plain water. The dissolved salts in saltwater lower its surface tension. So, this option is incorrect.
• Option B: As explained above, saltwater has a lower surface tension than pure water. Lower surface tension means smaller dewdrops. This option is correct.
• Option C: Saltwater is a homogeneous solution (a mixture where the salts are evenly distributed at the molecular level). It does not form lines because of the salt's crystalline structure in the context of dewdrop formation. The main factor is surface tension. So, this option is incorrect.
• Option D: Different liquids and solutions have different properties (such as surface tension, viscosity etc.). Not all of them will form the same large droplets as water. For example, alcohol has a lower surface tension than water and forms smaller droplets. So, this option is incorrect.

Answer:

B. If saltwater formed dewdrops, they would be smaller because saltwater's surface tension is lower than that of pure water.