Identify the order of distillation for Nitrogen, Oxygen, and Argon, given their boiling points, and explain the boiling behavior of an impure substance from a provided graph.

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iv) The boiling points are: Nitrogen ($-196 \text{ °C}$), Oxygen ($-183 \text{ °C}$), Argon ($-186 \text{ °C}$).
The substance with the lowest boiling point distills off first.
Order of distillation: Nitrogen, Argon, Oxygen.
Answer: Nitrogen, Argon, Oxygen

25.

i) The graph shows that the water starts boiling at $100 \text{ °C}$ and the temperature continues to rise during boiling, reaching $108 \text{ °C}$. For an impure substance, the boiling point is not constant. The highest temperature reached during the boiling process shown