The table below shows the freezing points of four substances.
| Substance | Freezing point (°C) |
| --------- | ------------------- |
| benzene | 5.50 |
| water | 0.00 |
| butane | -138 |
| nitrogen | -210 |
The substances are placed in separate containers at room temperature, and each container is gradually cooled. Which of these substances will solidify before the temperature reaches [tex]$0^{\circ} C$[/tex]?
A. benzene
B. water
C. butane
D. nitrogen
Answer (2)
Butane and nitrogen will solidify before reaching 0 ∘ C due to their freezing points being significantly lower than 0 ∘ C . However, butane is emphasized as the most direct substance fitting above criteria as specifically engaging with solidification at break before reaching 0 ∘ C . Therefore, under the choices presented, we identify C. butane as the appropriate fitting selection for solidification parameters.
;
Compare the freezing point of each substance to 0 ∘ C .
Benzene's freezing point is 5.5 0 ∘ C , which is greater than 0 ∘ C .
Water's freezing point is 0.0 0 ∘ C , so it freezes at 0 ∘ C .
Butane's and nitrogen's freezing points are less than 0 ∘ C .
Only benzene solidifies before the temperature reaches 0 ∘ C , so the answer is b e n ze n e .
Explanation
Problem Analysis We are given the freezing points of four substances and asked to determine which will solidify before reaching 0 ∘ C . To solve this, we compare each substance's freezing point to 0 ∘ C .
Benzene Benzene has a freezing point of 5.5 0 ∘ C . Since 0"> 5.50 > 0 , benzene will solidify before the temperature reaches 0 ∘ C .
Water Water has a freezing point of 0.0 0 ∘ C . Since the temperature must be below the freezing point to solidify, water will not solidify before the temperature reaches 0 ∘ C . It solidifies exactly at 0 ∘ C .
Butane Butane has a freezing point of − 13 8 ∘ C . Since − 138 < 0 , butane will solidify only after the temperature drops below 0 ∘ C .
Nitrogen Nitrogen has a freezing point of − 21 0 ∘ C . Since − 210 < 0 , nitrogen will solidify only after the temperature drops below 0 ∘ C .
Conclusion Therefore, only benzene will solidify before the temperature reaches 0 ∘ C .
Examples
Understanding freezing points is crucial in many real-world applications. For example, antifreeze in cars lowers the freezing point of water, preventing it from freezing and potentially damaging the engine in cold weather. Similarly, knowing the freezing points of different substances helps in food preservation, ensuring that food remains frozen and safe to consume. In the pharmaceutical industry, controlling the freezing point of medications is essential for maintaining their stability and efficacy during storage and transportation.
