As the temperature decreases, what happens to the viscosity of water?

• A. Decreases
• B. Increases
• C. Remains the same
• D. Fluctuates

Answer: (B)

As the temperature decreases, the viscosity of water increases. Viscosity is a measure of a fluid's resistance to flow. When the temperature of water drops, the molecules move more slowly because they have less kinetic energy. As a result, the interactions between the water molecules become stronger, leading to a greater resistance to movement. This increased friction among the slower-moving molecules is what raises the viscosity of the fluid.

In contrast, when the temperature rises, the molecules gain energy, move faster, and intermolecular interactions weaken, leading to a decrease in viscosity. Understanding the relationship between temperature and viscosity is crucial in wastewater management, as it can impact the movement and treatment of wastewater in various processes.