Final answer:
In cold climates, freezing point depression is exploited using salts for deicing roads and sidewalks, while covalent compounds such as ethylene glycol are used as antifreeze in vehicles and on airplanes to prevent corrosion and ice formation.
Step-by-step explanation:
Understanding freezing point depression and how substances like deicing fluids and antifreeze function is a practical application of chemistry, particularly in colder climates. Snow is the solid phase of water, formed from ice crystals that require significant heat to melt. In colder climates, despite temperatures rising above the freezing point during the day, snow can remain on the ground due to the time needed for that heat to transfer from the air to the snow.
To help accelerate the melting process, substances such as salt (sodium chloride or calcium chloride) are applied to roads and sidewalks for ice control. These materials work by lowering the freezing point of water, a phenomenon known as freezing point depression. However, while these ionic compounds are effective in deicing, they can cause metal corrosion, which is why they aren't suitable as antifreeze in vehicles or for deicing airplanes.
Instead, covalent compounds like ethylene glycol or propylene glycol are utilized in antifreeze and for deicing airplanes. These substances not only reduce the freezing point but also raise the boiling point of the liquid in which they are dissolved, making them valuable in both heating and cooling systems. When used on airplanes, heated glycols are sprayed on to clear existing ice and to prevent further ice formation on critical components such as control surfaces, ensuring flight safety.