Why Does Ice Melt Faster in Water?

Ice melts at different rates depending on how quickly it can absorb heat from its surroundings. Because water more readily absorbs temperature changes than air, the rate ice melts in these fluids is substantially different.

Phase Change

Water changes from a solid to a liquid because of an increase in heat. As molecules heat up, they vibrate and/or move faster; this makes it hard for them to maintain the bonds that keep them solid.

Specific Heat

The specific heat of a substance measures how much heat energy is required to raise 1 g of material by 1 degree of heat.

Water vs. Air

Water has a higher specific heat, so it can absorb or release more energy before changing temperature. Because heat flows out of extremes toward equilibrium, keeping ice in water warms it faster; in air, the gas around the ice quickly reaches a similar temperature and stops warming it.

Difference in Speed

Water can cool or heat an object 20 to 25 times faster than a similar object surrounded by air.

A Note on Temperature

All comparisons assume air and water of equal temperatures and in situations where the object is not affected by other nearby materials.

References

• Why Does Ice Melt Faster in Water Than in Air?
• Hypothermia
• Specific Heat