You are comparing the surface tension on two bodies of water: a fresh-water pond and a salt-water lagoon. Which one, if measured, would have a higher surface tension?
A: the fresh-water pond because it has a lower density
B: the salt-water pond because it has a higher density
C: the fresh-water pond because is has a lower pH
D: the salt-water pond because it has a higher pH
The correct option is A: the fresh-water pond because it has a lower density.
Surface tension is the property of the surface of a liquid that allows it to resist external forces. It is mainly determined by the cohesive forces between the liquid molecules. In general, surface tension is directly related to the intermolecular forces and inversely related to the density of the liquid.
Freshwater has a lower density compared to saltwater. Due to the lower density, the intermolecular forces between the water molecules in the freshwater pond are stronger, resulting in higher surface tension. Therefore, if measured, the fresh-water pond would have a higher surface tension.
The correct answer is A: the fresh-water pond because it has a lower density.
Surface tension is the force acting on the surface of a liquid that causes it to behave as if it were a stretched elastic membrane. It is caused by the cohesive forces between the molecules in the liquid. The greater the force of attraction between the molecules, the higher the surface tension.
In the case of water, fresh water typically has a lower density than saltwater. This means that the molecules in fresh water are less closely packed together compared to saltwater. With a lower density, the molecules in fresh water have a weaker force of attraction, resulting in higher surface tension.
Therefore, the fresh-water pond would generally have a higher surface tension compared to the salt-water lagoon.
To determine which body of water would have a higher surface tension, we need to understand the factors that affect surface tension. Surface tension is caused by the cohesive forces between the molecules at the surface of a liquid and is measured in units of force per unit length. It depends on factors such as intermolecular forces, temperature, and the presence of solutes.
In this case, the main factor that affects surface tension is the presence of solutes, specifically the type of solutes dissolved in the water. Freshwater typically has a lower concentration of dissolved salts compared to saltwater.
The correct answer is B: the salt-water lagoon because it has a higher density. The higher concentration of dissolved salts in saltwater increases its density, which leads to stronger intermolecular forces and thus higher surface tension.