How does increasing temperature affect diffusion rate and viscosity?

How does increasing temperature affect diffusion rate and viscosity?

• A. Both diffusion rate and viscosity increase.
• B. Diffusion rate decreases, viscosity increases.
• C. Diffusion rate increases, viscosity decreases.
• D. Diffusion rate stays the same, viscosity decreases.

Answer: (C)

Increasing temperature gives molecules more kinetic energy, so they move faster. Diffusion relies on this random motion: when particles zip around quicker, they encounter each other more often and mix more rapidly, so the diffusion rate goes up. Viscosity measures how much a liquid resists flowing; higher temperature weakens intermolecular forces relative to the molecules’ kinetic energy, allowing the liquid to flow more easily and thus lowering its viscosity. So, as temperature rises, diffusion speeds up while viscosity decreases. This matches the statement that diffusion rate increases and viscosity decreases. Everyday signs include dyes spreading faster in hot water and thick liquids like honey becoming runnier when heated.

Increasing temperature gives molecules more kinetic energy, so they move faster. Diffusion relies on this random motion: when particles zip around quicker, they encounter each other more often and mix more rapidly, so the diffusion rate goes up. Viscosity measures how much a liquid resists flowing; higher temperature weakens intermolecular forces relative to the molecules’ kinetic energy, allowing the liquid to flow more easily and thus lowering its viscosity. So, as temperature rises, diffusion speeds up while viscosity decreases. This matches the statement that diffusion rate increases and viscosity decreases. Everyday signs include dyes spreading faster in hot water and thick liquids like honey becoming runnier when heated.