Explain the following: (a) White phosphortus is chemically reactive while red phosphorus is not? (b) MgCl_(2).6H_(2)O cannot be made anhydrous simply by heating.

Explain the following: (a) White phosphortus is chemically reactive w

1.	Explain the following: (a) White phosphortus is chemically reactive while red phosphorus is not? (b) MgCl_(2).6H_(2)O cannot be made anhydrous simply by heating.
Answer» Solution :(a) White phosphorus `(MF P_(4))` has tetrahedral structure. Each P atom is linked with other three P-atoms by means of single bonds. The BOND PPP `(=90^(@))` is far less than tetrahedral ANGLE `109^(@) 28^(.)`. The molecule is, therefore, under strain and hence the molecule has tendency to open up and atomise. This is why `P_(4)` is reactive. Red phosphorus (MF `(P_(4))_(4)]` is polymer of white phosphorus. The integer n being very high, red phosphorus is having enormously high MW and it is for this reaction that red phosphorus is chemically inert. (b) `MgCl_(2).6H_(2)O` upon heating, loses 5 MOLECULES of WATER of hydration (crystallisation) easily to transform into mono hydrate `MgCl_(2).H_(2)O`. This upon further heating gets hydrolysed. `MgCl_(2).H_(2)O overset(Delta)to Mg(OH)Cl + HCl` `2Mg(OH)Cl overset(Delta)to Mg_(2)OCl_(2) + H_(2)O`