- #1
DallMall
- 1
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Hello,
Phosphorus may be present as different allotropes like white, red, violet or black phosphorus. All of them have a more or less different melting point. For example white phosphorus has a melting point of around 45 °C (source), while a red phosphorus has a melting point of around 590 or 610 °C (source, source).
Now my question is whether the liquid phosphorus obtained after melting any of these allotropes is actually the same liquid with same arrangement of phosphorus atoms into molecules?? If that is so than how is it possible for red phosphorus to have a melting point of around 600 °C while white phosphorus has a boiling point of about 280 °C (source)? If it was the same liquid then red (and black) phosphorus should not have a liquid form at all and simply sublimate.
Yet wikipedia disagrees and I quote: ''For some elements, allotropes have different molecular formulae which can persist in different phases – for example, two allotropes of oxygen (dioxygen, O2, and ozone, O3), can both exist in the solid, liquid and gaseous states. Conversely, some elements do not maintain distinct allotropes in different phases – for example phosphorus has numerous solid allotropes, which all revert to the same P4 form when melted to the liquid state.''
What do you think?
Phosphorus may be present as different allotropes like white, red, violet or black phosphorus. All of them have a more or less different melting point. For example white phosphorus has a melting point of around 45 °C (source), while a red phosphorus has a melting point of around 590 or 610 °C (source, source).
Now my question is whether the liquid phosphorus obtained after melting any of these allotropes is actually the same liquid with same arrangement of phosphorus atoms into molecules?? If that is so than how is it possible for red phosphorus to have a melting point of around 600 °C while white phosphorus has a boiling point of about 280 °C (source)? If it was the same liquid then red (and black) phosphorus should not have a liquid form at all and simply sublimate.
Yet wikipedia disagrees and I quote: ''For some elements, allotropes have different molecular formulae which can persist in different phases – for example, two allotropes of oxygen (dioxygen, O2, and ozone, O3), can both exist in the solid, liquid and gaseous states. Conversely, some elements do not maintain distinct allotropes in different phases – for example phosphorus has numerous solid allotropes, which all revert to the same P4 form when melted to the liquid state.''
What do you think?
