Question

\[{{C}_{60}}\] (bucky ball) is the cubic closest packed (face centered cubic) in its crystalline form. If you insert potassium atoms into all the tetrahedral and octahedral holes of the \[{{C}_{60}}\] structure, the formula would become\[{{K}_{x}}{{C}_{60}}\]. What is the value of \[x\].
a.) 1
b.) 2
c.) 3
d.) None of these

Answer 1

Hint: A fullerene is an allotrope form of carbon. Fullerene consists of carbon atoms connected by so many single and double bonds. The first fullerene discovered was\[{{C}_{60}}\]. \[{{C}_{60}}\] has a spherical shape.

Complete step by step answer:
\[{{C}_{60}}\] fullerene has 60 π electrons but a closed shell configuration needs 72 electrons.
The fullerene is capable of gaining the missing electrons by reaction with potassium.
After reaction of fullerene with potassium first it forms\[{{K}_{6}}C_{60}^{6-}\] salt and in continuation it forms \[{{K}_{12}}C_{60}^{12-}\].
 In these derivatives the bond length alternation is observed and the parental molecule has disappeared.
So, the correct option is Option D. Because fullerene reacts with greater than 12 potassium atoms to form \[{{K}_{12}}C_{60}^{12-}\].

Additional Information:
\[{{C}_{60}}\] fullerene has 60 π electrons but a closed shell configuration needs 72 electrons.
The fullerene is capable of gaining the missing electrons by reaction with potassium.
After reaction of fullerene with potassium first it forms\[{{K}_{6}}C_{60}^{6-}\] salt and in continuation it forms \[{{K}_{12}}C_{60}^{12-}\].
 In these derivatives the bond length alternation is observed and the parental molecule has disappeared.
So, the correct option is Option D. Because fullerene reacts with greater than 12 potassium atoms to form \[{{K}_{12}}C_{60}^{12-}\].

Note: Don’t be confused with the words fullerene and bucky ball. Both are the same.
A hollow spherical molecule containing a large number of carbon atoms is called a buckyball. Fullerene has the same structure as buckyball so fullerene is called a bucky ball.