Q. Which is the most reactive species of phosphorus?
AFMCAFMC 2003
Solution:
White Phosphorus or Yellow phosphorus
Red phosphorus
Black phosphorts
1
Prepared by heating phospinate rock with silica & coke at $11770 \,K$ in a electric furnace
White phosphorus $\xrightarrow{525\, K }$ Red phosphorus
White P $\xrightarrow{473 \,K }$ Black phosphorus high pressure (inert atm)
2
Soft waxy solid can be cut with a knife
Hard red solid sp. gravity $2.1$
Exist in three crystalline and one amorphous form
3
Poisnous
non-poisnous
non-poisnous
4
Insoluble in $H _{2} O$ soluble in $CS _{2}$
Insoluble both in $H _{2} O$ and $CS _{2}$
Insoluble in $H _{2} O$ and $CS _{2}$
5
On contact with air it undergoes slow combustion and glow in dark (chemilumines cence) It is less stable and more reactive form of phosphorus
More stable and chemically less reactive as compared to white phosphorus due polymeric structure.
It is most stable and least reactive form of phosphorus
| White Phosphorus or Yellow phosphorus | Red phosphorus | Black phosphorts | |
|---|---|---|---|
| 1 | Prepared by heating phospinate rock with silica & coke at $11770 \,K$ in a electric furnace | White phosphorus $\xrightarrow{525\, K }$ Red phosphorus | White P $\xrightarrow{473 \,K }$ Black phosphorus high pressure (inert atm) |
| 2 | Soft waxy solid can be cut with a knife | Hard red solid sp. gravity $2.1$ | Exist in three crystalline and one amorphous form |
| 3 | Poisnous | non-poisnous | non-poisnous |
| 4 | Insoluble in $H _{2} O$ soluble in $CS _{2}$ | Insoluble both in $H _{2} O$ and $CS _{2}$ | Insoluble in $H _{2} O$ and $CS _{2}$ |
| 5 | On contact with air it undergoes slow combustion and glow in dark (chemilumines cence) It is less stable and more reactive form of phosphorus | More stable and chemically less reactive as compared to white phosphorus due polymeric structure. | It is most stable and least reactive form of phosphorus |