Why phosphorus burns spontaneously in air?
請用A-Level 程度的知識去解答,如(bond angle, dipole moment... etc)
Please use the knowledge in A-Level Chemistry to explain. For example: bond angle, dipole moment, BP-BP replusion... etc)
bond angle, dipole moment 等等只是例子, 與問題的答案沒有任何必然性
感謝回答! 我都應該指明係white/yellow phosphorus!
- ?Lv 71 十年前最愛解答
又見廣告, 又是代餐, 又是這公司. 討爾死了.
LOK, this is actually related to bond angle and bond-bond repulsion.
phosphorus, or more specifically, white phosphorus, exists as simple molecule, P4.
the optimal bond angle for sp3-hybridized P atom is 109.5 degrees.
however, for P4 which adopts tetrahedral shapes, the bond angle is almost only 60*.
the bond-pairs have strong repulsion against the others, while the high ring strain speeds up breaking of the ring structure. the P4 is not very stable even under room conditions.
as a result, upon spontaneous cleavage of the P-P bond (which has low activation energy), it's prone to rapid oxidation in air, leading to spontaneous ignition.
red phosphorus and others are also allotropes of phosphorus, yet they're stable under air and room conditions. you have to specify which allotropes next time.
- LOKLv 51 十年前
關bonding, diploe moment, BP-BP repulsion咩事！？