Question

The Styx number for ${\mathrm{B}}_2{\mathrm{H}}_6$ is

• A. $2002$
• B. $2012$
• C. $2201$
• D. $2102$

Answer 1

The correct option is A

$2002$

The explanation for the correct statement

(A) $2002$

Styx Number:

• The Sytx number explains the relationship between the nature of bondings in borane and its structure.
• In Styx number, s stands for the number of three-centered, $\mathrm{B}-\mathrm{H}-\mathrm{B}$, bridge bonds.
• t is the number of three-centered $\mathrm{B}-\mathrm{B}-\mathrm{B}$ bonds.
• y is the number of two-centered $\mathrm{B}-\mathrm{B}$ bonds.
• x is the number of ${\mathrm{BH}}_2$ groups.

Styx Number for ${\mathrm{B}}_2{\mathrm{H}}_6$:

• Let ${\left(\mathrm{BH}\right)}_p{H}_q$ be the Boron Hydride's general formula.
• The structure of ${\mathrm{B}}_2{\mathrm{H}}_6$ is as follows,

Figure: Structure of ${\mathrm{B}}_2{\mathrm{H}}_6$

• For ${\mathrm{B}}_2{\mathrm{H}}_6$, the values of s, t, y and x are,
• $s=2;t=0;y=0;x=2$
• Therefore the Styx Number for ${\mathrm{B}}_2{\mathrm{H}}_6$ will be $2002$.

The explanation for the incorrect statements

(B) $2012$

• For the Styx number to be $2012$, the number of two-centered $\mathrm{B}-\mathrm{B}$ bonds needs to be equal to $1$.
• In case of ${\mathrm{B}}_2{\mathrm{H}}_6$ there is no two-centered $\mathrm{B}-\mathrm{B}$ bonds present.

(C) $2201$

• For the Styx number to be $2201$, the number of three-centered $\mathrm{B}-\mathrm{B}-\mathrm{B}$ bonds needs to be equal to $2$.
• In case of ${\mathrm{B}}_2{\mathrm{H}}_6$ there is no three-centered $\mathrm{B}-\mathrm{B}-\mathrm{B}$ bonds present.

(D) $2102$

• For the Styx number to be $2102$, the number of three-centered $\mathrm{B}-\mathrm{B}-\mathrm{B}$ bonds needs to be equal to $1$.
• In case of ${\mathrm{B}}_2{\mathrm{H}}_6$ there is no three-centered $\mathrm{B}-\mathrm{B}-\mathrm{B}$ bonds present.

Hence (A) is the correct option.