Final answer:
The speed of dissolving coffee in water is fastest in hot water because the molecular motion is greater, followed by tap water, with cold water being the slowest because molecules move less energetically.
Step-by-step explanation:
The speed of dissolving coffee in water varies depending on the temperature of the water. The rate of dissolution increases when the frequency and energy of collisions between solvent molecules and the solute particles increase. Hot water molecules move more rapidly compared to cold water molecules, leading to quicker dissolving due to more frequent and energetic collisions.
Hence, the correct ranking of the speed of dissolving coffee would be:
- Hot water
- Tap water
- Cold water
Given that the molecular motion is higher in hot water, coffee dissolves faster. In contrast, cold water with slower molecular motion has the slowest dissolving rate for coffee.