Question

The statement not true about graphite is:

• A. The three valence electrons of carbon take part in bond formation and fourth electron is free and mobile hence can conduct electricity.
• B. Graphite is denser than the diamonds
• C. The thermodynamic stability of graphite is more than the diamond
• D. All of these

Answer 1

The correct option is B

Graphite is denser than the diamonds

The explanation for the correct option

(B) Graphite is less dense than diamonds

1. Due to its more compact structure, diamond has a higher density than graphite.
2. In diamond, each carbon atom forms four covalent bonds in a tetrahedral form while in graphite, the carbon atom only forms three covalent bonds creating hexagonally packed carbon sheets.
3. Hence, option (B) is incorrect about graphite.

The explanation for incorrect options

(A) The three valence electrons of carbon take part in bond formation and the fourth electron is free and mobile and hence can conduct electricity.

1. In graphite, each carbon atom is attached to three other carbon atoms and forms only three bonds creating hexagonally packed carbon sheets.
2. Hence option (A) is correct about graphite.

(C) The thermodynamic stability of graphite is more than that of diamond

1. The thermodynamic stability is more because its enthalpy of formation is less than both diamond and fullerene.
2. Hence option (C) is correct about graphite.

Therefore, graphite is denser than diamonds, option (B) is correct.