Q.2-2-31a - Organic Chemistry (Mcmurry)

Question

Question: 

(A) The $H-Cl$ bond length is $136pm$. What would the dipole moment of $H-Cl$ be if the molecule were $100\%$ ionic, $H^{+}C{l}^{-}$?

(B) The actual dipole moment of HCl is $1.08 D$. What is the percent

ionic character of the $H-Cl$ bond?

Step-by-Step Solution

Answer

Answer

The dipole moment,  $\mu =6.523D$.

Step 1: Definition of Dipole moment

The dipole momentis defined as the magnitude of the charge at both ends of the molecular dipole multiplied by the distancerbetween the costs, which is the bond length.

Step 2: Formula used for calculation

 $\mu =Q\times r$

Dipole moments are expressed in Debye’s (D), where $1D=3.336\times {10}^{-30 }\left(C.m\right)$, coulomb meters are in SI units. Bond length is usually in pm, which is ${10}^{-12}$ m.

Step 3: Calculation of dipole moment

Formula to calculate dipole moment is: 

$\mu =Q\times r$

$\mu =\left(1.6\times {10}^{-19}C\right)\left(136\times {10}^{-12}m\right)\left(\frac{1D}{3.336\times {10}^{-30}C.m}\right)$

$\mu =6.523D$