Which of the following best describes the effect of increasing salinity on the density of water?

• A. Increasing salinity increases the density of water.
• B. Increasing salinity decreases the density of water.
• C. Increasing salinity first increases and then decreases the density of water.
• D. Salinity has no effect on the density of water.

Answer: (A)

Verified step by step guidance

1. Understand that density is defined as mass per unit volume, given by the formula \(\text{density} = \frac{\text{mass}}{\text{volume}}\).
2. Recognize that salinity refers to the amount of dissolved salts in water, which adds mass without significantly increasing the volume.
3. Consider that when salt dissolves in water, it increases the total mass of the solution while the volume increases only slightly, leading to an increase in density.
4. Recall that pure water has a certain density, and adding dissolved salts makes the solution denser because the mass increases more than the volume.
5. Conclude that increasing salinity results in an increase in the density of water.