Does Antifreeze Raise Boiling Point of Water? (Explained)

Last Updated on: 7th September 2023, 12:36 am

Antifreeze is a liquid mixture used in engines to lower the freezing point of the coolant fluid.

The most common antifreeze is ethylene glycol, although different formulations exist. Does antifreeze raise the boiling point of water?

Yes, antifreeze does raise the boiling point of water. The higher the content of ethylene glycol, the higher the boiling point will be. A 50:50 mixture of antifreeze raises the boiling point to 106℃ (223℉).

In this article, we’ll explain how antifreeze raises the boiling point of water and what temperatures you can expect.

How Antifreeze Raises Boiling Point of Water

The temperature at which a substance starts boiling depends on how strong the intermolecular forces are among its molecules.

Antifreeze elevates the boiling point of water by increasing the energy needed to pull the molecules apart from each other.

The main substance in antifreeze is ethylene glycol, it has a higher boiling point than similarly sized hydrocarbons because its molecules are attracted to each other through opposite charges.

This attractive force can be thought of as a kind of “molecular Velcro”, making it more difficult to separate the molecules and increasing how much energy is needed to boil the liquid.

Boiling and Freezing Point of Coolant vs Water

The introduction of antifreeze alters the boiling and freezing points of pure water. As the quantity of ethylene glycol increases, the freezing point decreases and the boiling point rises.

• 100% water: The boiling point of pure distilled water is 212°F (100°C) and it has a freezing point of 32°F (0°C) at sea level.
• 50/50 mixture: A 50/50 mixture of water and ethylene glycol raises the boiling point to 223°F (106°C) and lowers the freezing point to -35°F (-37°C) at sea level.
• 30/70 mixture: A 30/70 mixture of water and ethylene glycol raises the boiling point to 235°F (113°C) and reduces the freezing point to -67°F (-55°C) at sea level.

Does Antifreeze Prevent Water From Boiling?

Antifreeze does not prevent the boiling of water. Instead, it elevates the water’s boiling point, necessitating a higher temperature for boiling to occur.

Once the temperature gets to this increased boiling point, the water will boil.

Conclusion

Antifreeze is a liquid mixture used to lower the freezing point and raise the boiling point of water.

The addition of antifreeze, typically in the form of ethylene glycol, raises the boiling point of water. However, increasing the boiling point of water doesn’t prevent the liquid from boiling completely.