Question

Each of the following is true for white and red phosphorus except that they:
A) are both soluble in $ C{S_2} $
B) can be oxidized by heating in air
C) consist of the same kind of atoms
D) can be converted into one another

Answer 1

Hint: The crystal structure of red phosphorus has a complex network of bonding, whereas white phosphorus is made up of $ {P_4} $ molecules. To avoid natural combustion, white phosphorus must be contained in water, while red phosphorus is stable in air.

Complete answer:
A) are both soluble in $ C{S_2} $
White phosphorus, yellow phosphorus, or simply tetraphosphorus ( $ {P_4} $ ) are tetrahedral molecules made up of four atoms. Since phosphorus is a non-polar compound, it dissolves in non-polar solvents such as carbon disulphide ( $ C{S_2} $ ).
Red phosphorus is used in a polymeric form. As a result, red phosphorus has a far lower reactivity than white phosphorus. As a result of its polymeric composition, it is resistant to water and carbon disulphide.
Hence, this option is correct.
B) can be oxidized by heating in air
White phosphorus is a highly flammable substance. As exposed to oxygen, phosphorus will naturally combust. In air, phosphorus ignites at about $ {86^0}F $ ; when the air is dry, the ignition temperature is higher.
Red phosphorus is much more stable than white phosphorus because it has more atoms joined together in a network. It's not quite as flammable as white phosphorus, but it still reacts with air when given enough energy.
Hence, this option is incorrect.
C) Consist of the same kind of atoms
Phosphorus comes in a variety of shapes (allotropes) with a wide range of properties. White phosphorus and red phosphorus are the two most common allotropes. Hence, they consist of the same kind of atoms.
Hence, this option is incorrect.
D) can be converted into one another
White phosphorus can be converted to red phosphorus by heating it to $ {300^o}C $ ( $ {572^o}F $ ) in the absence of air or by exposing it to sunlight. The amorphous network of red phosphorus remains. The amorphous red phosphorus crystallises after further heating.
Hence, this option is incorrect.
Hence, the correct option is (A) are both soluble in $ C{S_2} $ .

Note:
Since white phosphorus has an angular strain in the $ {P_4} $ molecule with just $ {60^o} $ angles, it is more reactive than red phosphorus. In Red Phosphorus, there is no such angular strain.