Question

In graphite and diamond, the percentage of p-characters of the hybrid orbitals in hybridisation are respectively _______
A.50 and 75
B.67 and 75
C.33 and 25
D.33 and 75

Answer 1

We can calculate the percentage of p-characters by dividing the number of p-orbitals by the total number of orbitals multiplied by 100%. The formula to calculate the percentage of p-characters is,
Percentage of p-characters $= \dfrac{{{\text{Number of p - orbitals}}}}{{{\text{Total number of orbitals}}}} \times 100\%$

Complete step by step answer: We know that carbon shows various allotropic forms. Diamond has the hardest structure whereas graphite is one of the softest substances.
Diamond is transparent, and can be used as an electrical insulator and thermal conductor, whereas graphite is opaque, thermal insulator and good conductor of electricity.
We know that graphite is $s{p^2}$ hybridized and diamond is $s{p^3}$ hybridized.
Let us now calculate the percentage of p-characters in graphite.
Graphite is $s{p^2}$ hybridized. The number of p-orbitals in graphite is two and the total number of orbitals in graphite is three. From this, we can calculate the percentage of p-characters.
The formula to calculate the percentage of p-characters is,
Percentage of p-characters$= \dfrac{{{\text{Number of p - orbitals}}}}{{{\text{Total number of orbitals}}}} \times 100\%$
Percentage of p-characters=$\dfrac{2}{3} \times 100\%$
Percentage of p-characters=$67\%$
The percentage of p-characters in graphite is $67\%$.
Diamond is $s{p^3}$ hybridized. The number of p-orbitals in diamond is three and the total number of orbitals in diamond is four. From this, we can calculate the percentage of p-characters.
The formula to calculate the percentage of p-character is,
Percentage of p-characters $= \dfrac{{{\text{Number of p - orbitals}}}}{{{\text{Total number of orbitals}}}} \times 100\%$
Percentage of p-characters=$\dfrac{3}{4} \times 100\%$
Percentage of p-characters=$75\%$
The percentage of p-characters in diamond is $75\%$.
Therefore option B is correct.

Note: We can use graphite in pencil tips, electrodes, and dry cells. We can use diamonds for cutting, grinding, polishing and drilling in industry. We can use Graphite as anode in the electrolysis of alumina. Graphite prevents the liberation of a gas in the electrometallurgy of aluminum. Diamond does not conduct electricity, but graphite conducts electricity due to the presence of delocalized electrons that move between layers in graphite, whereas in diamond the particles are not charged to move freely.