Question

Which description explains events that take
place during the mixing? Select all that apply.

Warm water molecules move more
slowly than cold water molecules.

Collisions result in transfer of energy
from molecules of higher kinetic energy
to molecules of lower kinetic energy.

Warm water molecules slow down while
cold water molecules speed up.
Three containers are shown. The first two contain equal amounts of liquid. One is labeled 60 degrees Celsius and the other is labeled 10 degrees Celsius. Arrows from each point to the third container, which holds twice as much liquid and is labeled question mark degrees Celsius.

Answer 1

Select statements 2 and 3.

- Statement 2 is correct: collisions transfer energy from molecules with higher kinetic energy to those with lower kinetic energy.
- Statement 3 is correct: as a result, warm molecules slow down and cold molecules speed up.
- Statement 1 is incorrect: warm molecules move faster on average than cold ones.

(With equal amounts of water at 60°C and 10°C, the final temperature is (60 + 10)/2 = 35°C.)