Question

When the temperature is expected to drop below freezing, a farmer places large tubs of water in an unheated food storage shed. Write two or three sentences explaining why the farmer uses this technique to protect the produce from freezing. Hint: Remember that liquid water has more potential energy than ice.

Answer 1

The farmer uses this technique to protect the produce from freezing because as the water in the tubs begins to freeze, it releases heat. This heat can help to keep the surrounding air in the shed above freezing, protecting the produce from freezing as well. Additionally, as the water in the tubs freezes, it releases latent heat of fusion, which is the energy required to change a substance from a solid to a liquid. This energy is also released in the form of heat, further helping to keep the produce from freezing.