Which beaker shows a greater decrease in liquid level after being left side by side on a lab bench for 1 week, a beaker with 100.0 mL of pure water or a beaker with 100.0 mL of seawater, and why?

Verified step by step guidance

1. Identify the key difference between pure water and seawater: Pure water is composed solely of H2O molecules, while seawater contains dissolved salts and other substances.
2. Understand the concept of evaporation: Evaporation is the process where liquid molecules escape into the gas phase. It occurs more readily in pure substances due to fewer intermolecular forces compared to solutions.
3. Consider the effect of dissolved salts in seawater: The presence of salts in seawater increases the boiling point and decreases the vapor pressure compared to pure water, which means seawater evaporates more slowly.
4. Compare the evaporation rates: Since pure water has a higher vapor pressure than seawater, it will evaporate more quickly under the same conditions.
5. Conclude which beaker shows a greater decrease: The beaker with pure water will show a greater decrease in liquid level after one week due to its higher evaporation rate.