Final answer:
The freezing point of radiator fluid that is mixed with antifreeze would be significantly lower than 0°C, allowing it to withstand colder temperatures without freezing and causing damage to the car's engine.
Step-by-step explanation:
The question is asking about the freezing point of radiator fluid that is mixed with antifreeze, such as ethylene glycol (HOCH₂CH₂OH).
The freezing point of pure water is 0°C (32°F), but the addition of ethylene glycol, or antifreeze, to radiator fluid lowers the freezing point below that of water.
This is crucial because it prevents the fluid from freezing in the radiator, which could cause damage due to the expansion of ice.
The exact freezing point of a 50% (assuming the question was intended to mean a 50% mixture) antifreeze and water solution would be materially lower than 0°C, but without the specific concentration and the properties of the particular antifreeze used, we cannot provide an exact numerical value.
A common concentration for antifreeze in colder climates is around 30.2% ethylene glycol, which would still result in a significantly lower freezing point than pure water, thus offering substantial protection against freezing.